The death of his older brother Emperor Henry VI in 1197 meant that the Hohenstaufen rule (which reached as far as the Kingdom of Sicily) collapsed in imperial Italy and created a power vacuum to the north of the Alps. In an empire without a written constitution, reservations about the kingship of Henry VI's underage son, Frederick, led to two royal elections in 1198, which resulted in the German throne dispute: the two elected kings Philip of Swabia and the Welf Otto of Brunswick, claimed the throne for themselves. Both opponents tried in the following years through European and papal support, with the help of money and gifts, through demonstrative public appearances and rituals, to decide the conflict for oneself by raising ranks or by military and diplomatic measures. Philip was able to increasingly assert his kingship against Otto in the north part of the Alps. However, at the height of his power, he was assassinated in 1208. This ended the dispute for the throne; his opponent Otto of Brunswick quickly found recognition. Philip was the first German king to be murdered during his reign. In posterity, Philip is one of the little-noticed Hohenstaufen rulers.