In the first few months after his election as king, Philip failed to issue documents and thereby assert his kingship. His first surviving royal document, issued to Bishop Bertram of Metz, dated from Worms on 27 June 1198. Two days later, Philip forged an alliance with King Philip II of France. In Mainz Cathedral on 8 September 1198, it wasn't the Archbishop of Cologne, as usual, but Archbishop Aymon of Tarentaise who crowned Philip as German King. It is uncertain whether his wife was also crowned alongside him. Despite these violations of the "consuetudines" (Customs) when he was elected and crowned as King, Philip was able to unite the majority of the princes behind him. For the princes, property, ancestry and origins were essential for their support of Philip. Nevertheless, he knew that he had to settle the conflict with Otto and his supporters. A first attempt to mediate by Archbishop Conrad of Mainz in 1199 was rejected by the Welf.