The earliest known tribes formed the Hallstatt and La Tène cultures, named after the archaeological site of La Tène on the north side of Lake Neuchâtel. La Tène culture developed and flourished during the late Iron Age from around 450 BC,[35] possibly influenced by Greek and Etruscan civilisations. One of the most prominent La Tène tribes were the Helvetii, who primarily occupied the Swiss Plateau, alongside the Rhaetians in the eastern regions. Facing pressures from Germanic tribes, in 58 BC, the Helvetii, influenced by Orgetorix, a wealthy aristocrat, decided to abandon the Swiss Plateau for better opportunities in western Gallia. After Orgetorix's mysterious death, the tribe continued their migration but was decisively defeated by Julius Caesar's armies at the Battle of Bibracte, in present-day eastern France. Following their defeat, the Helvetii were forced by Caesar to return to their original lands, where they were subjected to stringent restrictions on their autonomy and movements.[35] In 15 BC, Tiberius (later the second Roman emperor) and his brother Drusus conquered the Alps, integrating them into the Roman Empire. The area occupied by the Helvetii first became part of Rome's Gallia Belgica province and then of its Germania Superior province. The eastern portion of modern Switzerland was integrated into the Roman province of Raetia. Sometime around the start of the Common Era, the Romans maintained a large camp called Vindonissa, now a ruin at the confluence of the Aare and Reuss rivers, near the town of Windisch.[37] The first and second century AD was an age of prosperity on the Swiss Plateau. Towns such as Aventicum, Iulia Equestris and Augusta Raurica reached a remarkable size, while hundreds of agricultural estates (Villae rusticae) were established in the countryside.[38] Around 260 AD, the fall of the Agri Decumates territory north of the Rhine transformed today's Switzerland into a frontier land of the Empire. Repeated raids by the Alamanni tribes provoked the ruin of the Roman towns and economy, forcing the population to shelter near Roman fortresses, like the Castrum Rauracense near Augusta Raurica. The Empire built another line of defence at the north border (the so-called Donau-Iller-Rhine-Limes). At the end of the fourth century, the increased Germanic pressure forced the Romans to abandon the linear defence concept. The Swiss Plateau was finally open to Germanic tribes.[citation needed] In the Early Middle Ages, from the end of the fourth century, the western extent of modern-day Switzerland was part of the territory of the Kings of the Burgundians, who introduced the French language to the area. The Alemanni settled the Swiss Plateau in the fifth century and the valleys of the Alps in the eighth century, forming Alemannia. Modern-day Switzerland was then divided between the kingdoms of Alemannia and Burgundy.[35] The entire region became part of the expanding Frankish Empire in the sixth century, following Clovis I's victory over the Alemanni at Tolbiac in 504 AD, and later Frankish domination of the Burgundians.[39][40] Throughout the rest of the sixth, seventh and eighth centuries, Swiss regions continued under Frankish hegemony (Merovingian and Carolingian dynasties) but after its extension under Charlemagne, the Frankish Empire was divided by the Treaty of Verdun in 843.[35] The territories of present-day Switzerland became divided into Middle Francia and East Francia until they were reunified under the Holy Roman Empire around 1000 AD.[35] In the 10th century, as the rule of the Carolingians waned, Magyars destroyed Basel in 917 and St. Gallen in 926. In response, Henry the Fowler, the then ruler of East Francia, decreed the fortification of key settlements to defend against these invasions. Large villages and towns, including strategic locations like Zurich and St.Gallen, were fortified. This initiative led to the development of what were essentially early urban strongholds and city governments in Eastern Switzerland.[38] By 1200, the Swiss Plateau comprised the dominions of the houses of Savoy, Zähringer, Habsburg, and Kyburg.[35] Some regions (Uri, Schwyz, Unterwalden, later known as Waldstätten) were accorded the Imperial immediacy to grant the empire direct control over the mountain passes. With the extinction of its male line in 1263, the Kyburg dynasty fell in AD 1264. The Habsburgs under King Rudolph I (Holy Roman Emperor in 1273) laid claim to the Kyburg lands and annexed them, extending their territory to the eastern Swiss Plateau.[39] Old Swiss Confederacy Main article: Old Swiss Confederacy Further information: Growth of the Old Swiss Confederacy, Reformation in Switzerland, and Early Modern Switzerland The Old Swiss Confederacy from 1291 (dark green) to the sixteenth century (light green) and its associates (blue). In the other colours shown are the subject territories. The 1291 Bundesbrief (federal charter) The Old Swiss Confederacy was an alliance among the valley communities of the central Alps. The Confederacy was governed by nobles and patricians of various cantons who facilitated management of common interests and ensured peace on mountain trade routes. The Federal Charter of 1291 is considered the confederacy's founding document, even though similar alliances likely existed decades earlier. The document was agreed among the rural communes of Uri, Schwyz, and Unterwalden.[41][page needed][42] By 1353, the three original cantons had joined with the cantons of Glarus and Zug and the Lucerne, Zurich and Bern city-states to form the "Old Confederacy" of eight states that obtained through the end of the 15th century.[42] The expansion led to increased power and wealth for the confederation. By 1460, the confederates controlled most of the territory south and west of the Rhine to the Alps and the Jura mountains, and the University of Basel was founded (with a faculty of medicine) establishing a tradition of chemical and medical research. This increased after victories against the Habsburgs (Battle of Sempach, Battle of Näfels), over Charles the Bold of Burgundy during the 1470s, and the success of the Swiss mercenaries. The Swiss victory in the Swabian War against the Swabian League of Emperor Maximilian I in 1499 amounted to de facto independence within the Holy Roman Empire.[42] In 1501, Basel[43] and Schaffhausen joined the Old Swiss Confederacy.[44] The Confederacy acquired a reputation of invincibility during these earlier wars, but expansion of the confederation suffered a setback in 1515 with the Swiss defeat in the Battle of Marignano. This ended the so-called "heroic" epoch of Swiss history.[42] The success of Zwingli's Reformation in some cantons led to inter-cantonal religious conflicts in 1529 and 1531 (Wars of Kappel). It was not until more than one hundred years after these internal wars that, in 1648, under the Peace of Westphalia, European countries recognised Switzerland's independence from the Holy Roman Empire and its neutrality.[39][40] During the Early Modern period of Swiss history, the growing authoritarianism of the patriciate families[45] combined with a financial crisis in the wake of the Thirty Years' War led to the Swiss peasant war of 1653. In the background to this struggle, the conflict between Catholic and Protestant cantons persisted, erupting in further violence at the First War of Villmergen, in 1656, and the Toggenburg War (or Second War of Villmergen), in 1712.