Under The Wittelsbach Dynasty
A new era began when, in consequence of Henry the Lion being placed under an imperial ban in 1180, Emperor Frederick I awarded the duchy to Otto, a member of the old Bavarian family of Wittelsbach, and a descendant of the counts of Scheyern. The Wittelsbach dynasty ruled Bavaria without interruption until 1918. Also the Electorate of the Palatinate was acquired by the Wittelsbach in 1214.
When Otto of Wittelsbach gained Bavaria at Altenburg in September 1180 the duchy's borders comprised the Böhmerwald, the Inn, the Alps and the Lech; and the duke exercised practical power only over his extensive private domains around Wittelsbach, Kelheim and Straubing.
Otto only enjoyed his rule for three years. His son Louis I succeeded him in 1183, played a leading part in German affairs during the early years of the reign of the emperor Frederick II, and died (assassinated) at Kelheim in September 1231. His son Otto II, called the Illustrious, the next duke, found that his loyalty to the Hohenstaufen emperors saw himself placed under a papal ban and Bavaria placed under an interdict. Like his father, Otto II increased the area of his lands by purchases, and he considerably strengthened his hold upon the duchy before he died in November 1253.
Read more about this topic: History Of Bavaria