Otto IV (1175-1218) was the third son of the rebellious Duke Henry the Lion, as well as being the nephew and foster son of King Richard Lionheart of England. He was born and raised in England by Richard, and therefore many consider him the first foreign king of Germany. When Emperor Henry VI died in 1197, some of the princes opposed to the Staufen dynasty elected Otto as anti-king in 1198.

Otto's election sparked a civil war between himself and Philip of Swabia, brother of Emperor Henry and true claimant to the crown of Germany. Otto's forces were initially victorious, but his situation eventually worsened and by 1207, Philip had all but won. His sudden murder a year later changed things considerably however, with Otto quickly becoming the recognised King of Germany, King of Italy and Holy Roman Emperor by 1209.