Why did Pope Innocent III first support Otto of Brunswick for the imperial throne?

Pope Innocent III initially supported Otto of Brunswick for the imperial throne primarily to protect the interests of the Papal States and to maintain the independence of the Kingdom of Sicily.1

Following the death of Emperor Henry VI in 1197, the papacy sought to prevent the unification of the German and Sicilian crowns, as any ruler holding both would pose a significant threat to papal territory. Innocent III was particularly wary of the ambitions of the Hohenstaufen candidate, Philip of Swabia, and viewed Otto as a more favorable alternative. Furthermore, Innocent aimed to preserve traditional papal rights regarding the imperial succession and used the electoral dispute to assert the pope's authority to evaluate and approve candidates for the throne. Otto secured this support in 1201 by agreeing to the papacy's territorial claims in central Italy.213