Pfennig - Leopold VI and Friedrich II

The joint reign designation here reflects a brief and politically awkward co-rulership: Leopold VI, Duke of Austria and Styria, died in 1230, and his son Friedrich II — later called "the Warlike" — had been associated with governance before assuming sole control. Friedrich would go on to extract significant constitutional concessions from Emperor Frederick II in 1237, briefly making Austria a duchy nearly independent of imperial authority, before dying without heirs at the Battle of the Leitha in 1246, extinguishing the Babenberg line entirely.