Sion is one of the most important pre-historic sites in Europe. The alluvial fan of
Sionne, the rocky slopes above the river and, to a lesser extent, Valeria and Tourbillon hills have been settled nearly continuously since antiquity. The oldest trace of human settlement comes from 6200 BC during the late Mesolithic. Around 5800 BC early Neolithic farmers from the Mediterranean settled in Sion. The settlements remained small until about 4500 BC, during the middle Neolithic, when the number of settlements increased sharply. To support the population increase, farming and grazing spread throughout the valley. They also began burying their dead in Chablandes-type stone burial cists with engraved anthropomorphic stelae. The individual graves changed at the beginning of the 3rd millennium BC in large, dry stone wall communal tombs (such as the Dolmen of Le Petit-Chasseur). During the Beaker culture period in the second half of the third Millennium, dolmens were built once again, but they were smaller and had no podium. Stelae continued to be carved, though these were rich with geometric patterns and sometimes built out of old dolmen. At the beginning of the Early Bronze Age (around 2300 BC) the last stelae were erected.
The early settlements have been well documented. There are huts from the Middle Neolithic period found near Le Petit Chasseur and under Ritz Avenue. Late Neolithic sites have been found at Bramois and the early Early Bronze Age site is at Le Petit Chasseur. The Middle Bronze Age, however, is poorly documented. From the subsequent epochs, the great necropolis of Don Bosco (the "aristocrat" tumulus of the Late Bronze Age and Iron Age) and the necropolis of Sous-le-Scex from the La Tène culture.
Celtic and Roman town
At the end of the 1st century BC, Sion was the capital of the Seduni, one of the four Celtic tribes of the Valais Julius Caesar mentions them as Nantuates Sedunos Veragrosque. They were conquered by the Romans in the 10s BC. By 8–7 BC, Emperor Augustus praised the tribe (civitas) of the Seduni with an inscription. The town-hall is said to contain several Roman inscriptions, one of which found at Sion commemorates the Roman presence: Civitas Sedunorum Patrono. Under the Romans it was known as Sedunum.
The Roman settlement stretched mainly from what is now St. Theodul, between the Sionne and to the west side of the hill, Valeria. Under the church, a large bath complex was discovered and partially excavated. Near La Sitterie, Sous-le-Scex and in the upper part of the Avenue du Petit Chasseur, portions of several villae suburbana were found. In the 1st century AD, the Claudii Vallensium Forum, in what is now Martigny, became the capital of the civitas Vallensium. Sedunum lost political importance, but still remained the home of many notable families. Grave stelae attest to the presence of duumviri (magistrates of the civitas), of flamines (priests of the imperial cult), a Roman knight and a former consuls in the town. In the 4th century praesides (provincial governors) are mentioned living in Sedunum, including a man named Pontius Asclepiodotus, who rebuilt an imperial building and, according to an inscription, converted to Christianity in 377.
Seat of a Catholic bishop
Valais between 1260–1337.
The Roman Catholic diocese of Sion is the oldest in Switzerland and one of the oldest north of the Alps. At first the see was sited at Octodurum, now called Martigny/Martinach. The first authentically historical bishop was Saint Theodore or Theodolus (died 391), who was present at the Council of Aquileia in 381. He founded the Abbey of Saint-Maurice in Agaunum, with a small church in honor of Saint Maurice, martyred there c. 300, when he united the local hermits in a common life, thus beginning the Abbey of Saint-Maurice, the oldest north of the Alps. Theodore rebuilt the church at Sion, which had been destroyed by Emperor Maximinus at the beginning of the 4th century. At first the new diocese was a suffragan of the archdiocese of Vienne; later it became suffragan of Tarentaise.
In 589 the bishop, St. Heliodorus, transferred the see to Sion, leaving the low-lying, flood-prone site of Octodurum, where the Drance joins the Rhône. Though frequently the early bishops were also abbots of Saint-Maurice, the monastic community was jealously watchful that the bishops should not extend their jurisdiction over the abbey. Several of the bishops united both offices:
Wilcharius (764–780), previously archbishop of Vienne, whence he had been driven by the Moors;
Saint Alteus, who received from the pope a bull of exemption in favor of the monastery (780); Aimo II, son of Count Humbert I of Savoy, who entertained Leo IX at Saint-Maurice in 1049.
The first cathedral probably dates from the 6th century. It was halfway up the hill, where later the church of St. Peter stood, until the 19th century when that church was demolished.
The fortunes of the city grew when the bishop settled there. In 999, King Rodolphe III of Burgundy granted the entire
County of Valais to the Bishop, and Sion became the capital of this County. The Prince-Bishop had the rights of high and low justice, the right to his own regalia and to appoint his own vassals. The residents of Sion were ruled by three appointees of the Bishop, the maior, the vice dominus or Viztum and the salterus.
Coat of Arms of Hildebrand Riedmatten, Bishop of Sion in 1594
As a result of the decline of the feudal social order and thanks to privileges and concessions granted by the bishop, the citizens of Sion had a limited independence in the Middle Ages. A contract between Bishop Kuno and his maior William of Turn from 1179, is seen as the first step in the creation of an independent city government. An agreement between the bishop, the collegiate church of St. Viztums and William of Turn in 1217 is the first written charter of freedom for the city. It includes civil and criminal laws and punishments as well as trade and market regulations. In 1269, the burghers of the town had their own council with its own statutes. The council governed the use and management of the common lands through twelve councilors led by the Viztum. These administrators later became syndics and were known by this title in 1323. In 1338, the vicar general confirmed the existing rights and freedom of the citizens of Sion in a document. The document was renewed by the bishop in 1339 and was presented to each successive bishop to reconfirm after his election. In the same year, Emperor Louis the Bavarian raised Sion to a free imperial city and collected the surrounding lands into a barony. In 1346, the episcopal Viztum and the citizenry collectively wrote the police regulations. Sion was now a city with city walls, documented freedoms and the market right.
From the late middle ages to the end of the ancien régime
Sion in 1572, from Beschreibung vnd Contrafactur der vornembster Stät der Welt
, Köln 1582
Sion in 1640, from Topographia Helvetiae, Rhaetiae et Valesiae, 1642
From the middle of the 14th century to 1475, the history of Sion was filled with wars and destruction. Bishop Witschard Tavel tried to reduce the privileges of the cathedral collegiate chapter and the citizenry with the support of the Count of Savoy. In 1352, Sion was conquered, pillaged and plundered by an army from Savoy. In 1373, the Bishop bought back the majority of the fief of Sion from the de Greysier family. Majorie Castle became the Bishop's residence and the maior was now appointed by the Bishop every year. Sion was attacked and looted in 1384, again during the Raron affair in 1418 and finally in 1475 during the Burgundian Wars.
During this period, the citizenry strove to defend their acquired privileges and whenever possible to expand those rights. In 1414, the city council approved a new set of statutes for the citizens. In 1433, Bishop Andreas dei Benzi approved a strict set of regulations concerning the granting of citizenship rights to applicants. Two years later, in 1435, he allowed the city council to appoint the Bishop's representative to Sion. He retained only the right to approve or reject the council's choice. In 1560, the citizenry bought the office of Viztum from the feudal landholder, the de Chevron family. A year earlier the bishop assigned the office of salterus to the citizenry. So by the mid 16th century, the city enjoyed a nearly total autonomy.
In the 16th century, due to a strong immigration from the German-speaking Upper Valais, Sion/Sitten became almost totally German speaking. The town council minutes were written in Latin until 1540, when they changed to German. Official invoices changed to German in 1600.
The 17th and 18th Ccnturies were a peaceful time in Sion. The new city hall was built on Grand-Pont between 1657-65. In 1788, a fire broke out in the city. It damaged Majoria and Tourbillon castles and destroyed 115 of the 284 inhabited houses.
In the High Middle Ages, the residents of Sion were homines episcopi or people of the bishop. This was true both for the staff at the court as well as the serfs who tilled the land, and the craftsmen and traders. As the civic community gradually began to organize, they were no longer willing to automatically grant every new arrival the same rights as citizens. Those who were unwilling or unable to purchase citizenship, which cost about 60 shillings in 1326, but wished to live in Sion were classed as permanent residents and their descendants held the same status until they could buy their citizenship. The permanent residents were mainly workers, craftsmen (often originating from the Swiss Confederation and the Germanies) and traders (mostly from Savoy and northern Italy). An outbreak of the plague in 1348 wiped out many citizens. In addition to the citizen's deaths, the restrictive attitude of the citizenry toward new members led to citizens becoming a minority in Sion. In the first population census in 1610 the town had 1,835 inhabitants, of whom 412 were citizens and 1,423 were permanent residents. In the 18th century, a third category, the tollerati, was added. On the eve of the revolution the city's population was 19% citizen, 30% permanent resident and 51% tollerati and other marginalized groups. There were only 41 citizen families, of which twelve were nobility and nine belonged to the patrician class.
Starting in the 13th century and the first half of the 14th century, long distance trade began to pick up from northern Italy via the Simplon Pass and through the Valais into the Champagne region. Sion became an important relay station on this route. The station at Sion included a Sust or warehouse that also provided additional animals to help haul wagons over the pass. Many local nobles and farmers were involved in animal husbandry to support the Sust and pastured their animals, during the summer, in pastures on the other side of the Rhône. The Sust's barns are stables were still in operation until the 19th century. Along the Sionne river, there were mills, saw mills and other industries that needed water power. In addition there were many tanneries in the same area. In 1466, the smiths, bricklayers and stonemasons' guilds arose from an ecclesiastical fraternity. Those three guilds were followed by the butchers' guild in 1512, the bakers' guild in 1525, the tailors and drapers' guild in 1527 and in 1602 the guild of shoemakers and tanners. These guilds played a major economic role in Sion until the end of the Ancien Régime. The Inn of the White Cross opened in 1550 for merchants and wealthy travelers, followed in 1688 by the inn of the Golden Lion, which was built beside the town hall.
Very little is known about the early churches in Sion since written sources are meager before the 12th century. The predecessor of the present cathedral, the church of Notre-Dame-du-Glarier in the Palacio district served both as the bishop's church and the parish church in the 12th century. It was destroyed in the 14th century during one of the wars between the Bishop of Sion and the House of Savoy. It was rebuilt in the second half of the 15th century. In the meantime, St. Peter's church took over as the bishop's and parish church. It was demolished in 1806. The Valeria Church was built in the 11th century and originally consecrated to St. Catherine. This church was probably the first church for the cathedral chapter. St. Theoduls church was first mentioned in the 13th century. It was probably built in 1100 on the ruins of Roman baths and a Carolingian era church. This church was probably built as a grave and pilgrimage church with a shrine in Theodul's Crypt. It was destroyed in the wars with the House of Savoy in the 14th century. Construction began on a new church in 1510–1516 under Bishop Matthew Schiner and continued until the 17th century. St. Theodul's served the French-speaking urban population as a parish church until 1798. In the 17th century, citizens claimed the right to choose their parish priest, over objections of the ecclesiastical authorities. The dispute eventually required mediation through the Papal Nuncio. The resolution allowed the citizens to choose the pastor from one of four proposed by the archbishop.
In the second half of the 16th century a large Protestant community grew in Sion under the leadership of renowned burghers, who had learned of the new doctrine while students in Bern, Basel, Zürich, Lausanne or Geneva. After 1604, the Valais government had clearly decided to remain part of the old faith. Some individuals or families emigrated to reformed areas, while others went back to the old faith. The Counter-Reformation, led by the Capuchin friars of Savoy and the Jesuits destroyed the last hopes of the Protestants to establish a foothold in the cathedral town. The Capuchins founded a monastery in 1631 and started construction of the monastery church in 1636, and the Jesuits started missionary activity in the 17th century and established a school in 1734.
From the Helvetic Republic to 1848
During the anti-patrician unrest in the Lower Valais at the end of the 18th century, Sion remained a bastion of the aristocracy. The leaders of the Les Crochets conspiracy were executed in 1791 in Sion to avoid riots. After the French invasion of Switzerland on 5 March 1798, Sion was caught between the revolutionary spirit of a portion of its population (who established a liberty pole in town on 10 March) and conservative elements who wanted to prevent any change in the Valais. Following the creation of the Helvetic Republic in May 1789, a counter-revolutionary rebellion erupted in the upper Valais. This short-lived rebellion was crushed on 17 May by French and Vaudois troops and Sion was plundered.
Under the Helvetic Republic, Sion was source of conflict between supporters and opponents of the new regime. In May 1799 counter revolutionary forces from Upper Valais looted the city again. In order to ensure peace in the Valais, the French General Louis Marie Turreau de Garambouville occupied Sion in 1801 and in 1802 Napoleon Bonaparte declared the independent Rhodanic Republic. It then remained independent until 1810 when it was annexed into France as the département of Simplon. Between 1798 and 1801 the representative of the Helvetic government resided in Sion. Under the French occupation, Joseph du Fay de Lavallaz was appointed by the emperor to be the mayor of the district of Sion.
After Napoleons defeats during the War of the Sixth Coalition the Valais was occupied by Austria at the end of December 1813. Under the Austrians, the citizenry received many of their rights back. During the following year, the government was split between supporters of the Ancien Régime and the supporters of the independent republic, with each party forming a council. When the two councils combined, the number of Council members was set to 20. Between 1815 and 1839, the patrician class gradually took more and more of the rights and duties of the citizenry back on themselves, gaining more and more power. In response to this, Alexandre de Torrente founded a liberal party in 1830. In the cantonal government, Sion agreed most often with the German-speaking Upper Valais. Which gave the Upper Valais a majority of the Zenden in the council, to the detriment of the French-speaking Lower Valais. However, after the vote on the constitution of 1839, the Upper Valais broke away from the rest of the canton. Sion was chosen as the capital of the Valais, while the breakaway Upper Valais chose Sierre. In 1840, the Upper and Lower Valais were reunited. But four years later, Sion was occupied by Upper Valais troops during the beginning of the Sonderbund War. Federal troops occupied Sion in November 1847.
Sion lost to Turin, Italy in its bid to host the 2006 Winter Olympics. Sion also bid for the 2002 Winter Olympics, which it lost to Salt Lake City, and the 1976 Winter Olympics, which it lost to Denver (the games were reassigned to Innsbruck when Denver residents voted down additional funding). On 10 June 2019, Sion withdrew it's bid for the 2026 Winter Olympics after rejection in the referendum.
Archaeologists found six aligned standing stones in La Petit district in Sion in July 2019. These standing stones were found accidentally during the construction work of a residential building, in the same area where 30 such stones and the dolmens were found in 1960.
“This discovery is of prime importance to help us understand social rituals at the end of the Neolithic period (around 2,500BC) in central Europe,” was announced from the canton of Valais. According to the press release, a number of stones were noticed to have been intentionally broken.
Three of the standing stones were carved with markings. The largest of the stones assumed to be a male figure wearing geometrically decorated clothes with a sun-like motif around his face is about two tonnes.