imperial army to force his cousin to surrender. Henry's allies deserted him, and he finally had to submit to Frederick at an Imperial Diet in Erfurt in November 1181. Henry spent three years in exile at the court of his father-in-law Henry II of England in Normandy before being allowed back into Germany. He finished his days in Germany, as the much-diminished Duke of Brunswick. Frederick's desire for revenge was sated. Henry the Lion lived a relatively quiet life, sponsoring arts and architecture. Frederick's victory over Henry did not gain him as much in the German feudalistic system as it would have in the English feudalistic system. While in England the pledge of fealty went in a direct line from overlords to those under them, the Germans pledged oaths only to the direct overlord, so that in Henry's case, those below him in the feudal chain owed nothing to Frederick. Thus, despite the diminished stature of Henry the Lion, Frederick did not gain his allegiances. Frederick was faced with the reality of disorder among the German states, where continuous civil wars were waged between pretenders and the ambitious who wanted the crown for themselves. Italian unity under German rule was more myth than truth. Despite proclamations of German hegemony, the pope was the most powerful force in Italy. When Frederick returned to Germany after his defeat in northern Italy, he was a bitter and exhausted man. The German princes, far from being subordinated to royal control, were intensifying their hold on wealth and power in Germany and entrenching their positions. There began to be a generalized social desire to "create greater Germany" by conquering the Slavs to the east. Although the Italian city states had achieved a measure of independence from Frederick as a result of his failed fifth expedition into Italy, the emperor had not given up on his Italian dominions. In 1184, he held a massive celebration, the Diet of Pentecost, when his two eldest sons were knighted, and thousands of knights were invited from all over Germany. While payments upon the knighting of a son were part of the expectations of an overlord in England and France, only a "gift" was given in Germany for such an occasion. Frederick's monetary gain from this celebration is said to have been modest. Later in 1184, Frederick again moved into Italy, this time joining forces with the local rural nobility