Both sides strived for the coronation as Holy Roman Emperor by Pope Innocent III and with it the recognition of their rule. The pontiff himself acted tactically before decided on one of the conflicting parties; this gave the opportunity to contact the Holy See several times through letters and embassies. Pope Innocent III wanted to prevent by all means the "unio regni ad imperium" (the reunification of the Holy Roman Empire and the Kingdom of Sicily, whose liege lord he was and wanted to remain) and he was also concerned about the Hohenstaufen claims to central Italy. For the pontiff, the question of obedience was a decisive factor in determining which candidate would have the papal recognition ("favor apostolicus"). In contrast to Otto, Philip expressed himself much more cautiously towards the Pope on this question.