Otto IV, Holy Roman Emperor

Otto IV was Holy Roman Emperor from 1209 until his death in 1218, the only German king of the Welf dynasty. Raised largely in England and France as a follower of his uncle Richard the Lionheart, who made him Count of Poitou in 1196, he was elected King of Germany by one faction in a disputed 1198 election that touched off a decade of civil war, becoming sole king after his rival Philip of Swabia was killed in 1208. Crowned emperor by Pope Innocent III in 1209, he broke with the pope the following year over the Kingdom of Sicily and was excommunicated, then allied with England against France, sharing in its defeat at the Battle of Bouvines in 1214; abandoned by most of his supporters in 1215, he spent his final years in retirement near Brunswick.