Holy Roman emperor and German king. Son of Henry the Lion and nephew of Richard the Lion-Hearted. His succession in 1198 was contested by Philip of Swabia, the nominee of the Hohenstaufens. Philip’s seizure of the Diocese of Mainz, Germany caused Pope Innocent III to support Otto who, in return, made generous concessions to the Holy See, thus aiding Innocent‘s ambition to be overlord of Italy. Public opinion turned toward Philip, however in 1204-1205, and Innocent deserted Otto. Philip, triumphant, was murdered at Bamberg, and Otto, by marrying Philip’s daughter, overcame all opposition. Crowned at Rome, Italy in 1209, he immediately laid claim to Sicily, was excommunicated, and Frederick II set up as his rival. Frederick was supported by France and the German princes, and Otto’s cause was lost by the defeat of his supporters at the Battle of Bouvines on 27 July 1214. Before his death, the order of excommunication on Otto was removed.