 Complete the following phrase:  After the Peace of Schönbrunn Willisen took vacation from the Austrian Army but did not return into service. He lived in Teutschenthal near Halle Saale, where he was captured as a deserter in 1811 and imprisoned at Kassel. He escaped out of prison and returned into Prussian service after his official release out of Austrian service. Willisen fought in the a hrefWar20of20the20Sixth20Coalition23War20in20GermanyNapoleonic battles of 181314a as a member of the staff of the Prussian Silesian Army and became a captain in Gebhard Leberecht von Blüchers staff in 1815. He remained in the Prussian generalstaff after Napoleons defeat and became a teacher of Art of War and History of War at the Prussian Military Academy. He published several books and opposed the views of Carl von Clausewitz. About 1830 Willisen also criticized the Russian warfare in the Napoleonic wars and showed his sympathy towards the 