By the time of Frederick's death in 1250, little centralized power remained in Germany. The Great Interregnum, a period in which there were several elected rival kings, none of whom was able to achieve any position of authority, followed the death of Frederick's son King Conrad IV of Germany in 1254. The German princes vied for individual advantage and managed to strip many powers away from the diminished monarchy. Rather than establish sovereign states however, many nobles tended to look after their families. Their many male heirs created more and smaller estates, and from a largely free class of officials previously formed, many of these assumed or acquired hereditary rights to administrative and legal offices. These trends compounded political fragmentation within Germany. The period was ended in 1273 with the election of Rudolph of Habsburg, a godson of Frederick.