Philip of Swabia (1177-1208) was the youngest son of Holy Roman Empeor Frederick I Barbarossa. He was thus brother to Emperor Henry VI and uncle to Emperor Frederick II.
Following the death of Henry VI, because the future Frederick II was too young (he was 3 years old), Philip presented his candidacy to the German throne. The result of the election saw the nomination of both Philip and Otto IV as Kings of Germany, and the two then were at war up until Philip of Swabia was assassinated in 1208. Following this, Otto IV, being the only remaining German King, was crowned as Holy Roman Emperor in 1209.
But what would be the consequences of Philip of Swabia not being assassinated?