Civil War among German Princes (1160s)

Timeline

1. 1160–1162Northern Italy—Germany · GermanyFrederick I repeatedly marched south to Italy to suppress the city-states, staying away from Germany for long periods. The emperor relied on princes such as Duke Henry the Lion of Saxony to govern in his absence, but Henry used the opportunity to expand his lands and foster allies, intensifying tensions between imperial authority and powerful vassals.
2. 1163–1166Bavaria–Saxony border · GermanyHenry the Lion belonged to the Welf family, which had both a long-standing feud and cooperation with the Hohenstaufen imperial house. In the mid-1160s the two sides repeatedly clashed over fief boundaries, episcopal appointments, and the Bavarian succession; local knights and towns were forced to choose sides, and small-scale armed conflicts were frequent.
3. 1167–1169Various parts of Germany · GermanyAfter forming the Lombard League in Italy, Frederick returned north and around 1167 convened a princely assembly to restore order, but Henry refused to join the imperial expedition to Italy, making their rift public. By the late 1160s Germany had fallen into a cold war between emperor and princes, with fragmentation increasingly apparent.