There are archaeological traces of human settlement since the late Paleolithic. Early Slavonic settlements on Lech Hill and Maiden Hill are dated to the 8th century. At the beginning of the 10th century this was the site of several places sacred to the Slavic religion. The ducal stronghold was founded just before AD 940 on Lech Hill, and surrounded by some fortified suburbs and open settlements.
Legend of Lech, Czech and Rus
According to the Polish version of a legend, three brothers went hunting together but each of them followed a different prey and eventually they all traveled in different directions. Rus went to the east, Čech headed to the west to settle on the Říp Mountain rising up from the Bohemian hilly countryside, while Lech traveled north. There, while hunting, he followed his arrow and suddenly found himself face-to-face with a fierce, white eagle guarding its nest from intruders. Seeing the eagle against the red of the setting sun, Lech took this as a good omen and decided to settle there. He named his Gniezno (Polish gniazdo – 'nest') in commemoration and adopted the White Eagle as his coat-of-arms. The white eagle remains a symbol of Poland to this day, and the colors of the eagle and the setting sun are depicted in Poland's coat of arms, as well as its flag, with a white stripe on top for the eagle, and a red stripe on the bottom for the sunset. According to Wielkopolska Chronicle (13th century), Slavs are descendants of
Pan, a Pannonian prince. He had three sons – Lech (the oldest), Rus, and Čech (the youngest), who decided to settle west, north, and east.
Cradle of the Polish state
Around AD 940 Gniezno, being an important pagan cult center, became one of the main fortresses of the early Piast rulers, along with aforementioned fortresses at Giecz, Kruszwica, Poznań, Kalisz, Łęczyca, Ostrów Lednicki, Płock, Włocławek, and others. Archeological excavations on Lech Hill in 2010 discovered an 11th-century tomb by the foundations of St. George's church, near the remains of a pagan burial mound discovered earlier on the hill. Discoveries indicate that Lech Hill could have been the burial place of rulers even before the baptism of Mieszko I. After the adoption of Christianity by Mieszko I, his son Bolesław I Chrobry deposed the remains of Saint Adalbert in a church, newly built on the Hill, to underline Gniezno's importance as the religious centre and capital of his kingdom.
Congress of Gniezno
It is here that the Congress of Gniezno took place in the year 1000 AD, during which Bolesław I the Brave, Duke of Poland, received Holy Roman Emperor Otto III. The emperor and the Polish duke celebrated the foundation of the Polish ecclesiastical province (archbishopric) in Gniezno, along with newly established bishoprics in Kołobrzeg for Pomerania; Wrocław for Silesia; Kraków for Lesser Poland in addition to the bishopric in Poznań for western Greater Poland, which was established in 968.
Royal coronation site
The 10th-century Gniezno Cathedral witnessed the royal coronations of Bolesław I in 1024 and his son Mieszko II Lambert in 1025. The cities of Gniezno and nearby Poznań were captured, plundered and destroyed in 1038 by the Bohemian duke Bretislav I, which pushed the next Polish rulers to move the Polish capital to Kraków. The archepiscopal cathedral was reconstructed by the next ruler, Bolesław II the Generous, who was crowned king here in 1076.
In the next centuries Gniezno evolved as a regional seat of the eastern part of Greater Poland, and in 1238 municipal autonomy was granted by the duke Władysław Odonic. Gniezno was again the coronation site in 1295 and 1300.
Regional site of Greater Poland
The city was destroyed again by the Teutonic Knights' invasion in 1331, and after an administrative reform became a county within the Kalisz Voivodeship (since the 14th century till 1768). Gniezno was hit by heavy fires in 1515, 1613, was destroyed during the Swedish invasion wars of the 17th–18th centuries and by a plague in 1708–1710. All this caused depopulation and economic decline, but the city was soon revived during the 18th century to become the Gniezno Voivodeship in 1768.
Gniezno was annexed by the Kingdom of Prussia in the 1793 Second Partition of Poland and renamed Gnesen, becoming part of the province of South Prussia. During the Kościuszko Uprising, the Polish army under General Jan Henryk Dąbrowski liberated the town on 22 August 1794 and defeated a Prussian Army north of Gnesen near Labischin (Łabiszyn) on 29 September 1794. But because of Kościuszko's defeat at the Battle of Maciejowice he gave up his plan to winter in Bromberg (Bydgoszcz) and moved through Thorn (Toruń) and retreated to central Poland. Thus, the Prussians retook it on 7 December 1794. During the Napoleonic Wars there was an uprising against Prussian rule. The French appeared in Gnesen in November 1806, and following General Jan Henryk Dabrowski's order issued to all towns and cities and country property owners to provide recruits for the organizing Polish forces, Gnesen initially provided 60 recruits who participated in the battles of 1806–07. Consequently, the town was included within the Duchy of Warsaw, but upon the defeat of Napoleon in Russia in 1812 it was occupied by the Russian army and was returned to Prussia in the 1815 Congress of Vienna. Gnesen was subsequently governed within Kreis Gnesen of the Grand Duchy of Posen and the later Province of Posen. Following the Greater Poland Uprising (1918–1919) and the Treaty of Versailles the town became part of the Second Polish Republic and reverted to its original name of Gniezno. Its citizen-soldiers joined the Polish army fighting the Bolsheviks during the Polish–Soviet War.
World War II
On 11 September 1939, after the invasion of Poland, Gniezno was occupied by German troops, and on 26 October 1939 it was annexed into Nazi Germany as part of Reichsgau Wartheland.
In late 1940 at the Sziekanka (Tiegenhof in German) psychiatric institute near Gniezno, 1172 patients were evacuated and then killed. Again in late 1940 hundreds of patients were gassed in gas van by the Lange Commando, a sub-unit of Einsatzkommando 2.
The town was liberated by the Red Army on 21 January 1945 and restored to Poland.