After the Romans departed, the kingdom of Burgundy ruled Western Switzerland, the Alemanni controlled central and eastern Switzerland, and the Alpine regions remained in the hands of local Gallo-Roman rulers.

The Romans withdraw

In the 3rd century the Germanic Alemanni conquered the Roman fortresses on the Rhine and invaded the Swiss Mittelland. From the 4th century onwards these Germanic peoples migrated ever westward, driven by the Huns and other peoples who had migrated from Central Asia and who were advancing into Europe.

Under the threat of migratory peoples, the Roman legions moved back from the provinces to the south of the Alps at the beginning of the 5th century. They wanted to concentrate their forces to the defense of their heartland (Rome and environs).

New linguistic boundaries emerge

In the period after the Romans linguistic boundaries began to form. The Alemanni moved into northern Switzerland in such large numbers that their language – a forerunner of today's dialects – gradually displaced the local language.
On the other hand, the Burgundians adopted the language of the local Gallo-Roman population (in what is now Western Switzerland) whom they ruled after the conquest of Savoy. By this time the Celtic dialect had given way to a form of Latin which developed into the various patois of Western Switzerland before being taken over by standard French.
Other regions ( Rhaetia, which the Alemanni failed to conquer and Ticino, which was under the rule of the Germanic Lombards) retained their Latin-related dialects, which developed into the languages (Romansh and Italian) currently spoken in this region.

The Franks in Switzerland

From the 6th century, the Franks, a Germanic people, gradually moved in from the west. They first conquered the Burgundy, and later also brought the Alemanni and the Lombards under their rule.
Two successive Frankish dynasties - the Merovingians and the Carolingians - prevailed for a lengthy period that culminated in the reign of Charlemagne the Great (742-814), after whom the Carolingian Dynasty was named. However, Charlemagne’s empire was divided up again in the 9th century after the death of his son Louis.
In 917 the present eastern and central Switzerland were under Swabian domination while Western Switzerland belonged to Burgundy. It was not until 1032 that the entire territory of modern Switzerland was governed by a single ruler, namely the German Emperor.

Invasions by the Saracens and Hungarians

During this period, parts of what is now Switzerland faced a variety of threats. Since the local noble families were constantly fighting to gain more power, the area was weak and attracted foreign invaders.
Hence in the 9th and 10th centuries several areas that are today part of Switzerland were threatened by the Saracens (Muslim colonialists). The exact origin of the Saracens is unclear. We only know that they moved from a base in Provence (southern France) towards northern Italy and conquered the western Alpine passes. Before they withdrew, they went as far as Chur and almost reached St. Gallen. The Saracens were eventually driven out by local Frankish armies. One of the Christian leaders who around 972 forced them off the Great St Bernard (then called Mons Jovis) was Bernard de Menthon who founded the hospice on the pass and after whom the mountain - and much later the rescue dogs who were trained there - were named.
At about the same time the Hungarians also posed a threat to the territory. The Hungarians originally came from Asia before reaching the Danube and wandering westwards. In 917 they destroyed Basel and later burnt down the monasteries of St. Gallen and Rheinau. It was only in 955 that the German King Otto I succeeded in driving out the Hungarians.

Related links

More about Swiss history