 Complete the following phrase:  Frederick II ; 25 April 1211  15 June 1246, known as Frederick the Quarrelsome Friedrich der Streitbare, 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 