The Great Interregnum of the medieval Holy Roman Empire occured after the death of emperor Frederick II.

The German princes, supported by the papacy, profited from the weakness of the last years of Hohenstaufen imperial rule and elected ineffectual kings.

The Pope Gregory X, to find support for a new crusade and to secure a counterweight to the king of Sicily, persuaded the princes to elect Count Rudolph of Habsburg emperor in 1273.