Various Germanic and Slavic tribes vied for control of the eastern Alpine-Danubian region following the withdrawal and collapse of Roman authority. Among the Germanic tribes, Alemanni (later known as Swabians) and Bavarians were the most notable. The Alemanni had arrived during the Roman era and by 500 were permanently established in most of modern-day Switzerland and the Austrian province of Vorarlberg. The early history of the Bavarians is not clear, but by the mid-500s, they were established alongside remnants of earlier, Romanized peoples in areas north and south of the present-day border between Austria and Germany. Both Swabians and Bavarians were subject to another Germanic tribe, the Franks, but effective Frankish control did not occur until the time of Emperor Charlemagne in the late 700s.

Slavic peoples, including Slovenes, Croats, Czechs, and Slovaks, settled in the region as subject peoples of the Avars, a nomadic tribe, and gradually absorbed their nomadic overlords. During the Carolingian era (eighth and ninth centuries), the areas of Slavic settlement, like those of the Swabians and Bavarians, became subject to the Franks.

Under Frankish patronage, Irish monks, most notably Saint Columban and Saint Gall, pioneered the Christian evangelization of the region in the seventh and eighth centuries. Their work gave rise to important monasteries whose agricultural activities on the frontiers of the Carolingian Empire helped open the region's primeval forests to wider settlement. Eventually integrated into the feudal political structure, the abbots of these monasteries vied with bishops and secular lords for religious and political influence well into the modern era. Bishoprics were established in four major Bavarian towns in the 730s. Salzburg, the only one of these to lie within modern Austria, was raised to the status of an archbishopric in 798 and was given jurisdiction over the other bishoprics. Salzburg became the center of the Christian evangelization efforts in the Slavic territories, which were instrumental in spreading the political reach of the Carolingian Empire.

Data as of December 1993