Pfennig - Imperial administration or interregnum

The dating range here brackets one of the most turbulent stretches in Austrian ducal history. Frederick II "the Quarrelsome" was deposed by Emperor Frederick II in 1236, leaving the duchy under direct imperial administration until the duke's restoration in 1239 — and then again in limbo after Frederick the Quarrelsome died without an heir at the Battle of the Leitha in 1246, triggering an interregnum that dragged on until Rudolf of Habsburg's eventual ascent decades later. Coins struck during these gaps in ducal authority are notoriously difficult to assign precisely, as the administrative machinery kept minting without consistent attribution.