Battle of Debrecen

As the Red Army advanced in October 1944, German units destroyed roads and rail lines and cut communications. They abducted Horthy after he tried to negotiate a peace with the Red Army and forced him to abandon his plans. Horty abdicated and intense fighting lasted for seven weeks outside Budapest. Destruction from both the Nazis and the Red Army left Hungary desolate. The last German troops were driven out on April 4, 1945.

http://www.worldwar2database.com/html/hungary.htm