Frederick II, known as Frederick the Quarrelsome, was Duke of Austria and Styria from 1230 until his death. He was the fifth and last Austrian duke from the House of Babenberg, since the former margraviate was elevated to a duchy by the 1156 Privilegium Minus. He was killed in the Battle of the Leitha River, leaving no male heirs.

The Duchy of Styria was a duchy located in modern-day southern Austria and northern Slovenia. It was a part of the Holy Roman Empire until its dissolution in 1806 and a Cisleithanian crown land of Austria-Hungary until its dissolution in 1918.