The duchy of
Upper Bavaria was created for the first time with the
First Bavarian partition in 1255 under duke
Louis II, but there was no exact correlation between this duchy and the current territory. After the reunification in 1340 Bavaria was divided again in 1349, and in 1392 the duchies
Bavaria-Munich and
Bavaria-Ingolstadt were created in Upper Bavaria. In 1505 Bavaria was permanently reunited. For administrative purposes, Bavaria was split into
Rentämter (plural of ''''). Upper Bavaria consisted of the Rentamt Munich and Rentamt Burghausen. After the founding of the
Kingdom of Bavaria the state was totally reorganised and, in 1808, divided into 15 administrative districts (Regierungsbezirke (singular Regierungsbezirk)), in Bavaria called (Kreise (singular Kreis)). They were created in the fashion of the French departements, quite even in size and population, and named after their main rivers. In the following years, due to territorial changes (e. g. loss of Tyrol, addition of the
Palatinate), the number of districts was reduced to 8. One of these was the
Isarkreis (Isar District). In 1837 king
Ludwig I of Bavaria renamed the Kreise after historical names, and tribes. This also involved border changes or territorial swaps. Thus, the Isarkreis changed to Upper Bavaria. Instead of a Rentamt-style mere administrational unit, the newly created districts became predecessors of modern regional self-government, building a political and administrational link in-between the Bavarian state as a whole and the local authorities. == Main sights ==