The Byzantine navy was the naval force of the East Roman or Byzantine Empire. Like the empire it served, it was a direct continuation from its Imperial Roman predecessor, but played a far greater role in the defence and survival of the state than its earlier iteration. While the fleets of the unified Roman Empire faced few great naval threats, operating as a policing force vastly inferior in power and prestige to the legions, the sea became vital to the very existence of the Byzantine state, which several historians have called a "maritime empire".
The first threat to Roman hegemony in the Mediterranean was posed by the Vandals in the 5th century, but their threat was ended by the wars of Justinian I in the 6th century. The re-establishment of a permanently maintained fleet and the introduction of the dromon galley in the same period also marks the point when the Byzantine navy began departing from its late Roman roots and developing its own characteristic identity. This process would be furthered with the onset of the Muslim conquests in the 7th century. Following the loss of the Levant and later Africa, the Mediterranean Sea was transformed from a "Roman lake" into a battleground between Byzantines and Arabs. In this struggle, the Byzantine fleets were critical, not only for the defence of the Empire's far-flung possessions around the Mediterranean basin, but also for repelling seaborne attacks against the imperial capital of Constantinople itself. Through the use of the newly invented "Greek fire", the Byzantine navy's best-known and feared secret weapon, Constantinople was saved from several sieges and numerous naval engagements were won for the Byzantines.
Initially, the defence of the Byzantine coasts and the approaches to Constantinople was borne by the great fleet of the Karabisianoi. Progressively however it was split up into several regional (thematic) fleets, while a central Imperial Fleet was maintained at Constantinople, guarding the city and forming the core of naval expeditions. By the late 8th century, the Byzantine navy, a well-organized and maintained force, was again the dominant maritime power in the Mediterranean. The antagonism with the Muslim navies continued with alternating success, but in the 10th century, the Byzantines were able to recover a position of supremacy in the Eastern Mediterranean.
During the 11th century, the navy, like the Empire itself, began to decline. Faced with new naval challenges from the West, the Byzantines were increasingly forced to rely on the navies of Italian city-states like Venice and Genoa, with disastrous effects on Byzantium's economy and sovereignty. A period of recovery under the Komnenians was followed by another period of decline, which culminated in the disastrous dissolution of the Empire by the Fourth Crusade in 1204. After the Empire was restored in 1261, several emperors of the Palaiologan dynasty tried to revive the navy, but their efforts had only a temporary effect. By the mid-14th century, the Byzantine fleet, which once could put hundreds of warships to sea, was limited to a few dozen at best, and control of the Aegean passed definitively to the Italian and Ottoman navies. The diminished navy, however, continued to be active until the fall of the Byzantine Empire to the Ottomans in 1453.
Civil wars and barbarian invasions: the 4th and 5th centuries
By the late 5th century, the Western Mediterranean had fallen into the hands of barbarian kingdoms. The conquests of Justinian I restored Roman control over the entire sea, which would last until the Muslim conquests in the latter half of the 7th century.
The Byzantine navy, like the Eastern Roman or Byzantine Empire itself, was a continuation of the Roman Empire and its institutions. After the Battle of Actium in 31 BC, in the absence of any external threat in the Mediterranean, the Roman navy performed mostly policing and escort duties. Massive sea battles, like those fought in the Punic Wars, no longer occurred, and the Roman fleets were composed of relatively small vessels, best suited to their new tasks. By the early 4th century, the permanent Roman fleets had dwindled, so that when the fleets of the rival emperors Constantine the Great and Liciniusclashed in 324 AD, they were composed to a great extent of newly built or commandeered ships from the port cities of the Eastern Mediterranean. The civil wars of the 4th and early 5th centuries, however, did spur a revival of naval activity, with fleets mostly employed to transport armies. Considerable naval forces continued to be employed in the Western Mediterranean throughout the first quarter of the fifth century, especially from North Africa, but Rome's mastery of the Mediterranean was challenged when Africa was overrun by the Vandals over a period of fifteen years.
The new Vandalic Kingdom of Carthage, under the capable king Geiseric, immediately launched raids against the coasts of Italy and Greece, even sacking and plundering Rome in 455. The Vandal raids continued unabated over the next two decades, despite repeated Roman attempts to defeat them. The Western Empire was impotent, its navy having dwindled to almost nothing, but the eastern emperors could still call upon the resources and naval expertise of the eastern Mediterranean. A first Eastern expedition in 448, however, went no further than Sicily, and in 460, the Vandals attacked and destroyed a Western Roman invasion fleet at Cartagena in Spain. Finally, in 468, a huge Eastern expedition was assembled under Basiliscus, reputedly numbering 1,113 ships and 100,000 men, but it failed disastrously. About 600 ships were lost to fire ships, and the financial cost of 130,000 pounds of gold and 700 000 pounds of silver nearly bankrupted the Empire. This forced the Romans to come to terms with Geiseric and sign a peace treaty. After Geiseric's death in 477, however, the Vandal threat receded.
Sixth century – Justinian restores Roman control over the Mediterranean
The 6th century marked the rebirth of Roman naval power. In 508, as antagonism with the Ostrogothic Kingdom of Theodoric flared up, the Emperor Anastasius I (491–518) is reported to have sent a fleet of 100 warships to raid the coasts of Italy. In 513, the general Vitalian revolted against Anastasius. The rebels assembled a fleet of 200 ships which, despite some initial successes, were destroyed by admiral Marinus, who employed a sulphur-based incendiary substance to defeat them.
In 533, taking advantage of the absence of the Vandal fleet, sent to suppress a revolt in Sardinia, an army of 15,000 under Belisarius was transported to Africa by an invasion fleet of 92 dromons and 500 transports, beginning the Vandalic War, the first of the wars of reconquest of Emperor Justinian I (527–565). These were largely amphibious operations, made possible by the control of the Mediterranean waterways, and the fleet played a vital role in carrying supplies and reinforcements to the widely dispersed Byzantine expeditionary forces and garrisons. This fact was not lost on the Byzantines' enemies. Already in the 520s, Theodoric had planned to build a massive fleet directed against the Byzantines and the Vandals, but his death in 526 limited the extent to which these plans were realized. In 535, the Gothic War began with a double-pronged Byzantine offensive, with a fleet again carrying Belisarius' army to Sicily and then Italy, and another army invading Dalmatia. Byzantine control of the sea was of great strategic importance, allowing the smaller Byzantine army to successfully occupy the peninsula by 540.
In 541 however, the new Ostrogoth king, Totila, created a fleet of 400 warships with which to deny the seas around Italy to the Empire. Two Byzantine fleets were destroyed near Naples in 542, and in 546, Belisarius personally commanded 200 ships against the Gothic fleet that blockaded the mouths of the Tiber, in an unsuccessful effort to relieve Rome. In 550, Totila invaded Sicily, and over the next year, his 300-ship fleet captured Sardinia and Corsica, and raided Corfu and the coast of Epirus. However, a defeat in a sea battle off Sena Gallica marked the beginning of the final Imperial ascendancy. With the final conquest of Italy and southern Spain under Justinian, the Mediterranean once again became a "Roman lake".
Despite the subsequent loss of much of Italy to the Lombards, the Byzantines maintained control of the seas around the peninsula. As the Lombards rarely ventured to sea, the Byzantines were able to retain several coastal strips of Italian territory for centuries. The only major naval action of the next 80 years occurred during the Siege of Constantinople by the Sassanid Persians, Avars and Slavs in 626. During that siege, the Slavs' fleet of monoxyla was intercepted by the Byzantine fleet and destroyed, denying the Persian army passage across the Bosporus and eventually forcing the Avars to retreat.
Map of the main Byzantine-Muslim naval operations and battles in the Mediterranean, 7th–11th centuries.
During the 640s, the Muslim conquest of Syria and Egypt created a new threat to Byzantium. Not only did the Arabs conquer significant recruiting and revenue-producing areas, but, after the utility of a strong navy was demonstrated by the short-lived Byzantine recapture of Alexandria in 644, they took to creating a navy of their own. In this effort the new Muslim elite, which came from the inland-oriented northern part of the Arabian peninsula, largely relied on the resources and manpower of the conquered Levant (especially the Copts of Egypt), which until a few years previously had provided ships and crews for the Byzantines. There is, however, evidence that in the new naval bases in Palestine shipwrights from Persia and Iraq were also employed. The lack of illustrations earlier than the 14th century means that nothing is known about the specifics of the early Muslim warships, although it is usually assumed that their naval efforts drew upon the existing Mediterranean maritime tradition. Given a largely shared nautical nomenclature, and the centuries-long interaction between the two cultures, Byzantine and Arab ships shared many similarities. This similarity also extended to tactics and general fleet organization; translations of Byzantine military manuals were available to the Arab admirals.
"At that time Kallinikos, an artificer from Heliopolis, fled to the Romans. He had devised a sea fire which ignited the Arab ships and burned them with all hands. Thus it was that the Romans returned with victory and discovered the sea fire."
After seizing Cyprus in 649 and raiding Rhodes, Crete and Sicily, the young Arab navy decisively defeated the Byzantines under the personal command of Emperor Constans II (641–668) in the Battle of the Masts of 655. This catastrophic Byzantine defeat opened up the Mediterranean to the Arabs, and began a centuries-long series of naval conflicts over the control of the Mediterranean waterways. From the reign of Muawiyah I (661–680), raids intensified, as preparations were made for a great assault on Constantinople itself. In the long first Arab siege of Constantinople, the Byzantine fleet proved instrumental to the survival of the Empire: the Arab fleets were defeated through the use of its newly developed secret weapon, "Greek fire". The Muslim advance in Asia Minor and the Aegean was halted, and an agreement to a thirty-year truce concluded soon after.
In the 680s, Justinian II (685–695 and 705–711) paid attention to the needs of the navy, strengthening it by the resettlement of over 18,500 Mardaites along the southern coasts of the Empire, where they were employed as marines and rowers. Nevertheless, the Arab naval threat intensified as they gradually took control of North Africa in the 680s and 690s. The last Byzantine stronghold, Carthage, fell in 698, although a Byzantine naval expedition managed to briefly retake it. The Arab governor Musa bin Nusair built a new city and naval base at Tunis, and 1,000 Coptic shipwrights were brought to construct a new fleet, which would challenge Byzantine control of the western Mediterranean. Thus, from the early 8th century on, Muslim raids unfolded unceasingly against Byzantine holdings in the Western Mediterranean, especially Sicily. In addition, the new fleet would allow the Muslims to complete their conquest of the Maghreb and to successfully invade and capture most of the Visigoth-controlled Iberian Peninsula.
The Byzantines were unable to respond effectively to the Muslim advance in Africa, because the two decades between 695 and 715 were a period of great domestic turmoil. They did react with raids of their own in the East, such as the one in 709 against Egypt which captured the local admiral, but they also were aware of a coming onslaught: as Caliph al-Walid I (705–715) readied his forces for a renewed assault against Constantinople, Emperor Anastasios II (713–715) prepared the capital, and mounted an unsuccessful pre-emptive strike against the Muslim naval preparations. Anastasios was soon overthrown by Theodosius III (715–717), who in turn was replaced, just as the Muslim army was advancing through Anatolia, by Leo III the Isaurian (717–741). It was Leo III who faced the second and final Arab siege of Constantinople. The use of Greek fire, which devastated the Arab fleet, was again instrumental in the Byzantine victory, while a harsh winter and Bulgar attacks further sapped the besiegers' strength.
In the aftermath of the siege, the retreating remains of the Arab fleet were decimated in a storm, and Byzantine forces launched a counter-offensive, with a fleet sacking Laodicea and an army driving the Arabs from Asia Minor. For the next three decades, naval warfare featured constant raids from both sides, with the Byzantines launching repeated attacks against the Muslim naval bases in Syria (Laodicea), and Egypt (Damietta and Tinnis). In 727, a revolt of the thematic fleets, largely motivated by resentment against the Emperor's iconoclasm, was put down by the imperial fleet through use of Greek fire. Despite the losses this entailed, some 390 warships were reportedly sent to attack Damietta in 739, and in 746 the Byzantines decisively defeated the Alexandrian fleet at Keramaia in Cyprus, breaking the naval power of the Umayyad Caliphate.
The Byzantines followed this up with the destruction of the North African flotillas, and coupled their successes at sea with severe trading limitations imposed on Muslim traders. Given the Empire's new ability to control the waterways, this strangled Muslim maritime trade. With the collapse of the Umayyad state shortly thereafter and the increasing fragmentation of the Muslim world, the Byzantine navy was left as the sole organized naval force in the Mediterranean. Thus, during the latter half of the 8th century, the Byzantines enjoyed a second period of complete naval superiority. It is no coincidence that in the many Islamic apocalyptic texts composed and transmitted during the first and second Islamic centuries, the End Times are preceded by a seaborne Byzantine invasion. Many traditions from the period stress that manning the guard posts (ribāṭ) on the coasts of Syria is tantamount to partaking in the jihād, and authorities like Abu Hurayrah were cited as considering one day of ribāṭ more pious an act than a night of prayer in the Kaaba.
These successes enabled Emperor Constantine V (741–775) to shift the fleet from the Mediterranean to the Black Sea during his campaigns against the Bulgars in the 760s. In 763, a fleet of 800 ships carrying 9,600 cavalry and some infantry sailed to Anchialus, where he scored a significant victory, but in 766, a second fleet, allegedly of 2,600 ships, again bound for Anchialus, sank en route. At the same time however, the Isaurian emperors undermined Byzantium's naval strength: with the Arab threat gone for the moment, and with the largely iconodule naval themes staunchly opposed to their iconoclastic policies, the emperors reduced the navy's size and downgraded the naval themes.
The Byzantine naval predominance lasted until the early 9th century, when a succession of disasters at the hands of the resurgent Muslim fleets spelled its end and inaugurated an era that would represent the zenith of Muslim ascendancy. Already in 790, the Byzantines suffered a major defeat in the Gulf of Antalya, and raids against Cyprus and Crete recommenced during the reign of Harun al-Rashid (786–809). Around the Mediterranean, new powers were rising, foremost amongst them the Carolingian Empire, while in 803, the Pax Nicephori recognized the de facto independence of Byzantine Venice, which was further entrenched by the repulsion of a Byzantine attack in 809. At the same time, in Ifriqiya, the new Aghlabid dynasty was established, which immediately engaged in raids throughout the central Mediterranean.
The Byzantines, on the other hand, were weakened by a series of catastrophic defeats against the Bulgars, followed in 820 by the Revolt of Thomas the Slav, which attracted the support of a large part of the Byzantine armed forces, including the thematic fleets. Despite its suppression, the revolt had severely depleted the Empire's defences. As a result, Crete fell between 824 and 827 to a band of Andalusian exiles. Three successive Byzantine recovery attempts failed over the next few years, and the island became a base for Muslim piratical activity in the Aegean, radically upsetting the balance of power in the region. Despite some Byzantine successes over the Cretan corsairs, and the razing of Damietta by a Byzantine fleet of 85 ships in 853, Arab naval power in the Levant was steadily reviving under Abbasid rule. Further Byzantine attempts to recover Crete, in 843 and 866, were complete failures.
"During that time [...] the Muslims gained control over the whole Mediterranean. Their power and domination over it was vast. The Christian nations could do nothing against the Muslim fleets, anywhere in the Mediterranean. All the time, the Muslims rode its wave for conquest."
The situation was even worse in the West. A critical blow was inflicted on the Empire in 827, as the Aghlabids began the slow conquest of Sicily, aided by the defection of the Byzantine commander Euphemios and the island's thematic fleet. In 838, the Muslims crossed over into Italy, taking Taranto and Brindisi, followed soon by Bari. Venetian operations against them were unsuccessful, and throughout the 840s, the Arabs were freely raiding Italy and the Adriatic, even attacking Rome in 846. Attacks by the Lombards and Lothair I failed to dislodge the Muslims from Italy, while two large-scale Byzantine attempts to recover Sicily were heavily defeated in 840 and 859. By 850, the Muslim fleets, together with large numbers of independent ghazi raiders, had emerged as the major power of the Mediterranean, putting the Byzantines and the Christians in general on the defensive.
The same period, when a battered Byzantium defended itself against enemies on all fronts, also saw the emergence of a new, unexpected threat: the Rus' made their first appearance in Byzantine history with a raid against Paphlagonia in the 830s, followed by a major expedition in 860.
Byzantine Reconquest: the era of the Macedonian dynasty
During the course of the later 9th and the 10th century, as the Caliphate fractured into smaller states and Arab power became weakened, the Byzantines launched a series of successful campaigns against them. This "Byzantine Reconquest" was overseen by the able sovereigns of the Macedonian dynasty (867–1056), and marked the noontide of the Byzantine state.
Reign of Basil I
Gold solidus of Emperor Basil I the Macedonian. His patronage of the fleet resulted in several successes and was long remembered by the sailors, forming strong ties of loyalty to the Macedonian dynasty that were felt up until the reign of his grandson, Constantine VII.
In the West, the Muslims continued to make steady advances, as the local Byzantine forces proved inadequate: the Empire was forced to rely on the aid of their nominal Italian subjects, and had to resort to the transfer of the eastern fleets to Italy to achieve any progress. Following the fall of Enna in 855, the Byzantines were confined to the eastern shore of Sicily, and under increasing pressure. A relief expedition in 868 achieved little. Syracuse was attacked again in 869, and in 870, Malta fell to the Aghlabids. Muslim corsairs raided the Adriatic, and although they were driven out of Apulia, in the early 880s they established bases along the western Italian coast, from where they would not be completely dislodged until 915. In 878, Syracuse, the main Byzantine stronghold in Sicily, was attacked again and fell, largely because the Imperial Fleet was occupied with transporting marble for the construction of the Nea Ekklesia, Basil's new church. In 880, Ooryphas' successor, the droungariosNasar, scored a significant victory in a night battle over the Aghlabids who were raiding the Ionian Islands. He then proceeded to raid Sicily, carrying off much booty, before defeating another Muslim fleet off Punta Stilo. At the same time, another Byzantine squadron scored a significant victory at Naples. These successes allowed a short-lived Byzantine counter-offensive to develop in the West in the 870s and 880s under Nikephoros Phokas the Elder, expanding the Byzantine foothold in Apulia and Calabria and forming the thema of Longobardia, which would later evolve into the Catepanate of Italy. A heavy defeat off Milazzo in 888, however, signalled the virtual disappearance of major Byzantine naval activity in the seas around Italy for the next century.
Arab raids during the reign of Leo VI
The sack of Thessalonica by the Arabs under Leo of Tripoli in 904, as depicted in the Madrid Skylitzes manuscript. It was the most serious of a renewed wave of piratical raids by the Muslim navies in the Aegean Sea during Leo VI's reign.
Despite the successes under Basil, during the reign of his successor Leo VI the Wise (886–912), the Empire again faced serious threats. In the north, a war broke out against the Bulgarian Tsar Simeon, and a part of the Imperial Fleet was used in 895 to ferry an army of Magyars across the Danube to raid Bulgaria. The Bulgarian war produced several costly defeats, while at the same time the Arab naval threat reached new heights, with successive raids devastating the shores of Byzantium's naval heartland, the Aegean Sea. In 891 or 893, the Arab fleet sacked the island of Samos and took its stratēgos prisoner, and in 898, the eunuch admiral Raghib carried off 3,000 Byzantine sailors of the Kibyrrhaiotai as prisoners. These losses denuded Byzantine defences, opening the Aegean up to raids by the Syrian fleets. The first heavy blow came in 901, when the renegade Damian of Tarsus plundered Demetrias, while in the next year, Taormina, the Empire's last outpost in Sicily, fell to the Muslims. The greatest disaster, however, came in 904, when another renegade, Leo of Tripoli, raided the Aegean. His fleet penetrated even into the Dardanelles, before proceeding to sack the Empire's second city, Thessalonica, all while the Empire's fleet remained passive in the face of the Arabs' superior numbers. Furthermore, the Cretan corsairs' raids reached such intensity, that by the end of Leo's reign, most of the southern Aegean islands were either abandoned or forced to accept Muslim control and pay tribute to the pirates. It is no surprise that a defensive and cautious mindset is prevalent in the Leo's contemporary instructions on naval warfare (Naumachica).
The most distinguished Byzantine admiral of the period was Himerios, the logothetēs tou dromou. Appointed admiral in 904, he was unable to prevent the sack of Thessalonica, but he scored a first victory in 905 or 906, and in 910, he led a successful attack on Laodicea in Syria. The city was sacked and its hinterland plundered and ravaged without the loss of any ships. A year later, however, a huge expedition of 112 dromons and 75 pamphyloi with 43,000 men, that had sailed under Himerios against the Emirate of Crete, not only failed to recover the island, but on its return voyage, it was ambushed and comprehensively defeated by Leo of Tripoli off Chios (October 912).
The tide began to turn again after 920. Coincidentally, the same year witnessed the ascension of an admiral, Romanos Lekapenos (920–944), to the imperial throne, for the second (after Tiberios Apsimaros) and last time in the Empire's history. Finally, in 923, the decisive defeat of Leo of Tripoli off Lemnos, coupled with the death of Damian during a siege of a Byzantine fortress in the next year, marked the beginning of the Byzantine resurgence.
Recovery of Crete and the northern Levant
The siege of Chandax, the main Muslim stronghold in Crete, as depicted in the Madrid Skylitzes manuscript. Nikephoros Phokas led a huge amphibious operation which recovered Crete for the Empire, thus securing the Aegean Sea from the Muslim pirate threat.
The Empire's growing might was displayed in 942, when Emperor Romanos I dispatched a squadron to the Tyrrhenian Sea. Using Greek fire, the squadron destroyed a fleet of Muslim corsairs from Fraxinetum. In 949, however, another expedition of about 100 ships, launched by Constantine VII (945–959) against the Emirate of Crete, ended in disaster, due to the incompetence of its commander, Constantine Gongyles. A renewed offensive in Italy in 951–952 was defeated by the Fatimids, but another expedition in 956 and the loss of an Ifriqiyan fleet in a storm in 958 temporarily stabilized the situation in the peninsula. In 962, the Fatimids launched an assault on the remaining Byzantine strongholds on Sicily; Taormina fell on Christmas Day 962 and Rometta was besieged. In response, a major Byzantine expedition was launched in 964 but ended in disaster. The Fatimids defeated the Byzantine army before Rametta and then annihilated the fleet at the Battle of the Straits, notably through the use of divers bearing incendiary devices. Both powers focusing their attention elsewhere, a truce was concluded between Byzantium and the Fatimids in 967, which curbed Byzantine naval activity in the West: the seas of Italy were left to the local Byzantine forces and the various Italian states until after 1025, when Byzantium again actively intervened in southern Italy and Sicily.
In the East, in 956 the stratēgosBasil Hexamilites inflicted a crushing defeat on the Tarsos fleet, opening the way for another grand expedition to recover Crete. It was entrusted to Nikephoros Phokas, who in 960 set out with a fleet of 100 dromons, 200 chelandia, and 308 transports, carrying an overall force of 77,000 men, to subdue the island. The conquest of Crete removed the direct threat to the Aegean, Byzantium's naval heartland, while Phokas' subsequent operations led to the recovery of Cilicia (in 963), Cyprus (in 968), and the northern Syrian coast (in 969). These conquests removed the threat of the once mighty Muslim Syrian fleets, effectively re-establishing Byzantine dominance in the Eastern Mediterranean, so that Nikephoros Phokas could boast to Liutprand of Cremona with the words "I alone command the sea". A few raids and naval clashes occurred as antagonism with the Fatimids mounted in the late 990s, but peaceful relations were restored soon after, and the Eastern Mediterranean remained relatively calm for several decades to come.
"Strive at all time to have the fleet in top condition and to have it not want for anything. For the fleet is the glory of Rhōmania. [...] The droungarios and prōtonotarios of the fleet should [...] investigate with rigor the slightest thing which is done to the fleet. For when the fleet is reduced to nothingness, you shall be overthrown and fall."
Throughout most of the 11th century, the Byzantine navy faced few challenges. The Muslim threat had receded, as their navies declined and relations between the Fatimids, especially, and the Empire were largely peaceful. The last Arab raid against imperial territory was recorded in 1035 in the Cyclades, and was defeated in the next year. Another Rus' attack in 1043 was beaten back with ease, and with the exception of a short-lived attempt to recover Sicily under George Maniakes, no major naval expeditions were undertaken either. Inevitably, this long period of peace and prosperity led to complacency and neglect of the military. Already in the reign of Basil II (976–1025), the defence of the Adriatic was entrusted to the Venetians. Under Constantine IX (1042–1055), both the army and navy were reduced as military service was increasingly commuted in favour of cash payments, resulting in an increased dependency upon foreign mercenaries. The large thematic fleets declined and were replaced by small squadrons subject to the local military commanders, geared more towards the suppression of piracy than towards confronting a major maritime foe.
By the last quarter of the 11th century, the Byzantine navy was a shadow of its former self, having declined through neglect, the incompetence of its officers, and lack of funds.Kekaumenos, writing in c. 1078, laments that "on the pretext of reasonable patrols, [the Byzantine ships] are doing nothing else but ferrying wheat, barley, pulse, cheese, wine, meat, olive oil, a great deal of money, and anything else" from the islands and coasts of the Aegean, while they "flee [the enemy] before they have even caught sight of them, and thus become an embarrassment to the Romans". By the time Kekaumenos wrote, new and powerful adversaries had risen. In the West, the NormanKingdom of Sicily, which had expelled the Byzantines from Southern Italy and had conquered Sicily, was now casting its eye on the Byzantine Adriatic coasts and beyond. In the East, the disastrous Battle of Manzikert in 1071 had resulted in the loss of Asia Minor, the Empire's military and economic heartland, to the Seljuk Turks, who by 1081 had established their capital at Nicaea, barely a hundred miles south of Constantinople. Soon after, Turkish as well as Christian pirates appeared in the Aegean. The Byzantine thematic fleets, which once policed the seas, were by then so depleted by neglect and the successive civil wars that they were incapable of responding effectively.
Attempts at recovery under Alexios I and John II
At this point, the sorry state of the Byzantine fleet had dire consequences. The Norman invasion could not be forestalled, and their army seized Corfu, landed unopposed in Epirus and laid siege to Dyrrhachium, starting a decade of war which consumed the scant resources of the embattled Empire. The new emperor, Alexios I Komnenos (1081–1118), was forced to call upon the assistance of the Venetians, who in the 1070s had already asserted their control of the Adriatic and Dalmatia against the Normans. In 1082, in exchange for their help, he granted them major trading concessions. This treaty, and subsequent extensions of these privileges, practically rendered the Byzantines hostage to the Venetians (and later also the Genoese and the Pisans). Historian John Birkenmeier notes that:
Byzantium's lack of a navy [...] meant that Venice could regularly extort economic privileges, determine whether invaders, such as the Normans or Crusaders entered the Empire, and parry any Byzantine attempts to restrict Venetian commercial or naval activity.
In the clashes with the Normans through the 1080s, the only effective Byzantine naval force was a squadron commanded, and possibly maintained, by Michael Maurex, a veteran naval commander of previous decades. Together with the Venetians, he initially prevailed over the Norman fleet, but the joint fleet was caught off guard and defeated by the Normans off Corfu in 1084.
Alexios inevitably realized the importance of having his own fleet, and despite his preoccupation with land operations, he took steps to re-establish the navy's strength. His efforts bore some success, especially in countering the attempts by Turkish emirs like Tzachas of Smyrna to launch fleets in the Aegean. The fleet under John Doukas was subsequently used to suppress revolts in Crete and Cyprus. With the aid of the Crusaders, Alexios was able to regain the coasts of Western Anatolia and expand his influence eastwards: in 1104, a Byzantine squadron of 10 ships captured Laodicea and other coastal towns as far as Tripoli. By 1118, Alexios was able to pass on a small navy to his successor, John II Komnenos (1118–1143). Like his father, John II concentrated on the army and regular land-based campaigns, but he took care to maintain the navy's strength and provisioning system. In 1122, however, John refused to renew the trading privileges that Alexios had granted to the Venetians. In retaliation, the Venetians plundered several Byzantine islands, and, with the Byzantine fleet unable to confront them, John was forced to renew the treaty in 1125. Evidently the Byzantine navy at this point was not sufficiently powerful for John to successfully confront Venice, especially since there were other pressing demands on the Empire's resources. Not long after this incident, John II, acting on the advice of his finance minister
John of Poutza, is reported to have cut funding to the fleet and transferred it to the army, equipping ships on an ad hoc basis only.
Naval expeditions of Manuel I
The navy enjoyed a major comeback under the ambitious emperor Manuel I Komnenos (1143–1180), who used it extensively as a powerful tool of foreign policy in his relations with the Latin and Muslim states of the Eastern Mediterranean. During the early years of his reign, the Byzantine naval forces were still weak: in 1147, the fleet of Roger II of Sicily under George of Antioch was able to raid Corfu, the Ionian islands and into the Aegean almost unopposed. In the next year, with Venetian aid, an army accompanied by a very large fleet (allegedly 500 warships and 1,000 transports) was sent to recapture Corfu and the Ionian Islands from the Normans. In retaliation, a Norman fleet of 40 ships reached Constantinople itself, demonstrating in the Bosporus off the Great Palace and raiding its suburbs. On its return voyage however it was attacked and destroyed by a Byzantine or Venetian fleet.
In 1155, a Byzantine squadron of 10 ships in support of Norman rebel Robert III of Loritello arrived at Ancona, launching the last Byzantine bid to regain Southern Italy. Despite initial successes and reinforcements under megas doux Alexios Komnenos Bryennios, the expedition was ultimately defeated in 1156, and 4 Byzantine ships were captured. By 1169, the efforts of Manuel had evidently borne fruit, as a large and purely Byzantine fleet of about 150 galleys, 10-12 large transports and 60 horse transports under megas douxAndronikos Kontostephanos was sent to invade Egypt in cooperation with the ruler of the CrusaderKingdom of Jerusalem. The invasion failed however, and the Byzantines lost half the fleet in a storm on the way back.
Following the Empire-wide seizure and imprisonment of all Venetians in March 1171, the Byzantine fleet was strong enough to deter an outright attack by the Venetians, who sailed to Chios and settled for negotiations. Manuel sent a fleet of 150 ships under Kontostephanos to confront them there and employed delaying tactics, until, weakened by disease, the Venetians began to withdraw and were pursued by Kontostephanos' fleet. It was a remarkable reversal of fortunes, compared with the humiliation of 1125. In 1177, another fleet of 70 galleys and 80 auxiliary ships under Kontostephanos, destined for Egypt, returned home after appearing off Acre, as Count Philip of Flanders and many important nobles of the Kingdom of Jerusalem refused to participate in the campaign. However, by the end of Manuel's reign, the strains of constant warfare on all fronts and the Emperor's various grandiose projects had become evident: the historian Niketas Choniates attributes the rise of piracy in the latter years of Manuel's reign to the diversion of the funds intended for the maintenance of the fleet for other needs of the imperial treasury.
After the death of Manuel I and the subsequent demise of the Komnenian dynasty in 1185, the navy declined swiftly. The maintenance of galleys and the upkeep of proficient crews were very expensive, and neglect led to a rapid deterioration of the fleet. Already by 1182 the Byzantines had to pay Venetian mercenaries to crew some of their galleys, but in the 1180s, as the bulk of the Komnenian naval establishment persisted, expeditions of 70–100 ships are still recorded in contemporary sources. Thus Emperor Andronikos I Komnenos (1183–1185) could still gather 100 warships in 1185 to resist and later defeat a Norman fleet in the Sea of Marmara. However, the subsequent peace treaty included a clause which required the Normans to furnish a fleet for the Empire. This, together with a similar agreement made by Isaac II Angelos (1185–1195 and 1203–1204) with Venice the next year, in which the Republic would provide 40–100 galleys at six months' notice in exchange for favourable trading concessions, is a telling indication that the Byzantine government was aware of the inadequacy of its own naval establishment.
The period also saw the rise of piracy across the Eastern Mediterranean. Pirate activity was high in the Aegean, while pirate captains frequently offering themselves as mercenaries to one or the other of the region's powers, providing for the latter a quick and cheap way of raising a fleet for particular expeditions, without the costs of a standing navy. Thus a Byzantine fleet of 66 vessels sent by Isaac II to recapture Cyprus from Isaac Komnenos was destroyed by the pirate Margaritus of Brindisi, who was in the employ of the Normans of Sicily. The depredations of the pirates, especially the Genoese captain Kaphoures, described by Niketas Choniates and his brother, the Metropolitan of AthensMichael Choniates, finally forced the Angeloi to action. The fleet tax was once again levied from the coastal regions and a navy of 30 ships was equipped, which was entrusted to the Calabrian pirate
Steiriones. Despite scoring a few early successes, Steiriones' fleet was destroyed in a surprise attack by Kaphoures off Sestos. A second fleet, augmented by Pisan vessels and again commanded by Steiriones, was finally able to defeat Kaphoures and end his raids.
The Fall of Constantinople to the Fourth Crusade marked the triumph of the Latin West, and especially the Venetian maritime power, over the enfeebled Byzantine Empire.
At the same time, however, the then megas doux, Michael Stryphnos, was accused by Niketas Choniates of enriching himself by selling off the equipment of the imperial fleet, while by the early 13th century the authority of the central government had weakened to such an extent that various local potentates began seizing power in the provinces. The general atmosphere was one of lawlessness, which enabled men like Leo Sgouros in southern Greece and the imperial governor of Samos, Pegonites, to use their ships for their own purposes, launching raids of their own. Even Emperor Alexios III Angelos (1195–1203) is said to have licensed one of his commanders, Constantine Phrangopoulos, to launch pirate raids against commerce in the Black Sea.
The Byzantine state and its fleet were thus in no state to resist the naval might of Venice, which supported the Fourth Crusade. When Alexios III and Stryphnos were alerted to the fact that the Crusade was sailing for Constantinople, only 20 "wretched and decayed" vessels could be found, according to Niketas Choniates. During the first Crusader siege of the city in 1203, the attempts of the Byzantine ships to oppose the Crusader fleet from entering the Golden Horn were repulsed, and the Byzantine attempt to employ fireships failed due to the Venetians' skill at handling their ships.
After the capture of Constantinople by the Fourth Crusade in 1204, the Byzantine Empire was partitioned between the Crusaders, while three Greek successor states were set up, the Despotate of Epirus, the Empire of Trebizond, and the Empire of Nicaea, each claiming the Byzantine imperial title. The former did not maintain a fleet, the Trapezuntine navy was minuscule and mostly used for patrols and transporting troops, while the Nicaeans initially followed a policy of consolidation and used their fleet for coastal defence. Under John III Vatatzes (1222–1254), a more energetic foreign policy was pursued, and in 1225, the Nicaean fleet was able to occupy the islands of Lesbos, Chios, Samos, and Icaria. It was, however, no match for the Venetians: attempting to blockade Constantinople in 1235, the Nicaean navy was defeated by a far smaller Venetian force, and in another similar attempt in 1241, the Nicaeans were again routed. Nicaean efforts during the 1230s to support a local rebellion in Crete against Venice were also only partially successful, with the last Nicaean troops being forced to leave the island in 1236. Aware of the weakness of his navy, in March 1261 the Emperor Michael VIII Palaiologos (1259–1282) concluded the Treaty of Nymphaeum with the Genoese, securing their aid against Venice at sea, in return for commercial privileges.
Emperor Michael VIII Palaiologos. He restored the Byzantine Empire by recapturing Constantinople, and was responsible for the last flourishing of Byzantium as a major naval power.
Following the recapture of Constantinople a few months later however, Michael VIII was able to focus his attention on building up his own fleet. In the early 1260s, the Byzantine navy was still weak, and depended still greatly on Genoese aid. Even so, the allies were not able to stand up to Venice in a direct confrontation, as evidenced by the defeat of a combined Byzantine–Genoese fleet of 48 ships by a much smaller Venetian fleet in 1263. Taking advantage of the Italians' preoccupation with the ongoing Venetian–Genoese war, by 1270 Michael's efforts had produced a strong navy of 80 ships, with several Latin privateers sailing under imperial colours. In the same year, a fleet of 24 galleys besieged the town of Oreos in Negroponte (Euboea), and defeated a Latin fleet of 20 galleys. This marked the first successful independent Byzantine naval operation and the beginning of an organized naval campaign in the Aegean that would continue throughout the 1270s and would result in the recapture, albeit briefly, of many islands from the Latins.
This revival did not last long. Following the death of Charles of Anjou in 1285 and the end of the threat of an invasion from Italy, Michael's successor Andronikos II Palaiologos (1282–1328) assumed that, by relying on the naval strength of his Genoese allies, he could do without the maintenance of a fleet, whose particularly heavy expenditure the increasingly cash-strapped treasury could no longer afford. At the same time, Andronikos was less concerned with the West and more with affairs in Asia Minor and his—eventually futile—attempt to stop the Turkish advance there, a policy where the fleet lacked a role. Consequently, the entire fleet was disbanded, its crews dismissed and the ships broken up or left to rot. The results were quick to follow: during Andronikos' long reign, the Turks gradually took permanent possession of the Aegean coasts of Anatolia, with the Empire unable to reverse the situation, while the Venetian fleet was able to attack Constantinople and raid its suburbs at will during the 1296–1302 war.
Andronikos' decision aroused considerable opposition and criticism from contemporary scholars and officials almost from the outset, and historians like Pachymeres and Nikephoros Gregoras dwell long on the disastrous long-term effects of this short-sighted decision: piracy flourished, often augmented by the crews of the disbanded fleet who took service under Turkish and Latin masters, Constantinople was rendered defenceless towards the Italian maritime powers, and more and more Aegean islands fell under foreign rule—including Chios to the Genoese Benedetto Zaccaria, Rhodes and the Dodecanese to the Hospitallers, Lesbos and other islands to the Gattilusi. As Gregoras commented, "if [the Byzantines] had remained masters of the seas, as they had been, then the Latins would not have grown so arrogant [...], nor would the Turks ever have gazed upon the sands of the [Aegean] sea, [...] nor would we have to pay to everyone tribute every year." After 1305, bowing to popular pressure and the need to contain the Catalan Company, the Emperor belatedly tried to rebuild the navy of 20 vessels, but although a few ships were built and a small fleet appears to have been active over the next couple of years, it eventually was disbanded again.
In the 14th century, recurrent civil wars, attacks from Bulgaria and Serbia in the Balkans and the devastation caused by ever-increasing Turkish raids hastened the collapse of the Byzantine state, which would culminate in its final fall to the Ottoman Turks in 1453. Several emperors after Andronikos II also tried to re-build a fleet, especially in order to secure the security and hence the independence of Constantinople itself from the interference of the Italian maritime powers, but their efforts produced only short-term results.
Thus Andronikos II's successor Andronikos III Palaiologos (1328–1341), immediately after his accession, with the help of contributions from various magnates, assembled a large fleet of reportedly 105 vessels. This he personally led in the last major foray of a Byzantine navy in the Aegean, recovering Chios and Phocaea from the Genoese and forcing various smaller Latin and Turkish principalities to come to terms with him. His campaigns against the Ottomans in Bithynia were failures, however, and soon the Ottomans had established their first naval base at Trigleia on the Sea of Marmara, from where they raided the coasts of Thrace. To defend against this new threat, towards the end of Andronikos III's reign a fleet of some 70 ships was built at Constantinople to oppose the Turkish raids, and headed by the megas douxAlexios Apokaukos. This fleet was very active during the civil war of 1341–1347, in which its commander played a prominent role. Following the civil war, Emperor John VI Kantakouzenos (1347–1354) tried to restore the navy and merchant fleet, as a means of both reducing the Empire's economic dependency on the Genoese colony of Galata, which controlled the trade passing through Constantinople, and of securing the control of the Dardanelles against passage by the Turks. To that end, he enlisted the aid of the Venetians, but in March 1349, his newly built fleet of nine warships and about 100 smaller vessels was caught in a storm off the southern shore of Constantinople. The inexperienced crews panicked, and the ships were either sunk or captured by the Genoese. Undeterred, Kantakouzenos launched another effort at building a fleet, which allowed him to re-establish Byzantine authority over Thessalonica and some coastal cities and islands. A core of this fleet was maintained at Constantinople, and although Byzantine ships remained active in the Aegean, and scored some successes over Turkish pirates, they were never able to stop their activities, let alone challenge the Italian navies for supremacy at sea. Lack of funds condemned the fleet to a mere handful of vessels maintained at Constantinople. It is characteristic that in his 1418 pamphlet to the despotēsTheodore II Palaiologos, the scholar Gemistos Plethon advises against the maintenance of a navy, on the grounds that resources were insufficient to adequately maintain both it and an effective army.
Henceforth, the impoverished Byzantine state became a pawn of the great powers of the day, trying to survive by exploiting their rivalries. Thus, for instance, in 1351, Kantakouzenos was induced to side with Venice in its war with Genoa, but, abandoned by the Venetian admirals, his fleet was easily defeated by the Genoese and he was forced to sign an unfavourable peace. During the brief usurpation of John VII in 1390, Manuel II (1391–1425) was able to gather only five galleys and four smaller vessels (including some from the Hospitallers of Rhodes) to recapture Constantinople and rescue his father John V. Six years later, Manuel promised to arm ten ships to assist the Crusade of Nicopolis; twenty years later, he personally commanded 4 galleys and 2 other vessels carrying some infantry and cavalry, and saved the island of Thasos from an invasion. Byzantine ships were active throughout the Ottoman Interregnum, when Byzantium sided with various rival Ottoman princes in turn. Manuel used his ships to ferry the rival pretenders and their forces across the Straits. With Genoese assistance, Manuel's fleet was also able to muster a fleet of eight galleys and capture Gallipoli in May 1410, albeit for a brief time; and in August 1411, the Byzantine fleet was instrumental in the failure of a siege of Constantinople by the Ottoman prince Musa Çelebi, when it defeated Musa's attempt to blockade the city by sea as well. Likewise, in 1421, 10 Byzantine warships were engaged in support of the Ottoman pretender Mustafa against Sultan Murad II.
The last recorded Byzantine naval victory occurred in 1427 in a battle off the Echinades Islands, when the Emperor John VIII Palaiologos (1425–1448) defeated the superior fleet of Carlo I Tocco, Count of Cephalonia and Despot of Epirus, forcing him to relinquish all his holdings in the Morea to the Byzantines. The last appearance of the Byzantine navy was in the final Ottoman siege of 1453, when a mixed fleet of Byzantine, Genoese and Venetian ships (varying numbers are provided by the sources, ranging from 10 to 39 vessels) defended Constantinople against the Ottoman fleet. During the siege, on 20 April 1453, the last naval engagement in Byzantine history took place, when three Genoese galleys escorting a Byzantine transport fought their way through the huge Ottoman blockade fleet and into the Golden Horn.