Here I Stand: Conscience and the Reformation
In the German-speaking lands of central Europe, there was no single king; there were many princes controlling relatively small areas. Moreover, the area's geographical distance from Rome and the longstanding sense that German people had never been part of the Roman Empire fueled a desire for the retention of their independence.
Many had long argued that Germany's resources -- its taxes and tithes -- had been sent off to Rome (the Empire, later the Church) for little in return. Thus, there was a great attraction to many of these princes in Luther's appeal that they, the princes -- as the leaders of their people --- should be their spiritual leaders as well.
Moreover, there was an incentive for local princes to take over churches in their territory -- they would control the tithe! Thus, the political situation in Germany -- where there was not a single kingdom and where ties to Rome were never that strong -- was one reason why Luther's ideas gained popularity, especially among the princes and nobles themselves.
But the pope claimed to be the highest power in Europe. In response to his heretical writings and especially his questioning of the authority of the pope, Luther was threatened with being ex-communicated (or excluded) from the Church. A special council, or Diet, of bishops was convened at the cathedral city of Worms, which demanded Luther recant his heretical views