Southern Germany is a region of Germany that included the areas in which Upper German dialects are spoken, which includes the stem duchies of Bavaria and Swabia in present-day Bavaria, Baden-Württemberg, and the southern portion of Hesse and Rhineland-Palatinate that were part of the Duchy of Franconia.

The Duchy of Bavaria was a frontier region in the southeastern part of the Merovingian kingdom from the sixth through the eighth century. It was settled by Bavarian tribes and ruled by dukes (duces) under Frankish overlordship. A new duchy was created from this area during the decline of the Carolingian Empire in the late ninth century. It became one of the stem duchies of the East Frankish realm which evolved as the Kingdom of Germany and the Holy Roman Empire.