Landshut stands on the River Isar, a tributary of the Danube, northeast of Munich and south of Regensburg. It was the capital of the Lower Bavarian Duchy, which was formed in 1255 and which reunited with Upper Bavaria in 1340: that Duchy is sometimes called Bavaria-Landshut.
In 1349 the sons of the late Emperor Louis the Bavarian, having ruled jointly for a while, divided up the Bavarian lands. Lower Bavaria was divided in two, Straubing in the north and Landshut in the south. Landshut went to Stephen II, the younger son of the Emperor’s first marriage. In 1363, when his nephew died, Stephen II added Upper Bavaria, ignoring the rights of his half-brothers, Louis VI and Otto V, who were trying to rule in Brandenburg. When he died in 1375 his three sons ruled the combined Duchy jointly until 1392, when the lands were again partitioned. The second brother took the Lower Bavarian Duchy of Landshut. Later part of Straubing (1425) and all of Ingolstadt (1445/7) were added. The last two Dukes of Bavaria-Landshut were both nicknamed der Reiche, “the Rich”, a name that speaks for itself.
Duke George (1479-1503) had no son. His daughter was married to Philip, a younger son of the Elector Palatine Philip, and it was George’s hope that his daughter and son-in-law would succeed him. Duke Albert IV of Bavaria-Munich, the heir male, claimed Bavria-Landshut, and the Reichskammergericht, the recently created supreme court, ruled in his favour, excepting those lands of royal interest. A short sharp war followed, during which both the heiress and her husband died of illness. Duke Albert reunited Bavaria. Maximilian, the Emperor-Elect, who had helped ensure the victory, took his cut in 1507, adding Kufstein and Rattenberg on the Inn and part of the Zillertal to help round off his Tirolese territory and Mondsee to supplement his Upper Austrian lands. The infant grandsons of Duke George received some of the Upper Palatinate, including Sulzbach, which had been Bohemian in the third quarter of the 14th century, and also Neuburg from the old Ingolstadt Duchy, also in 1507. These lands became known as der junge Pfalz, the junior Palatinate. To prevent further partition, Albert IV decreed in 1506 that the Bavarian lands should pass by primogeniture; another bitter family quarrel thwarted that decision, when in 1516 Duke William IV was forced to grant Landshut to his younger brother, Louis X. With the childless death of Louis in 1545 the last partition of Bavaria ended.