Operation Konrad III was a German military offensive on the Eastern Front of the Second World War. It was the third and most ambitious of the three Konrad Operations and had the objective of relieving the siege of Budapest and recapturing the entire Transdanubia region. Achieving complete surprise, the German offensive began on 18 January 1945. Supported by the Luftwaffe, the IV SS Panzer Corps, the principal German attack formation, overran the Soviet 4th Guards Army in two days, destroying hundreds of Soviet tanks along the way, reached the Danube river on 19 January and recaptured 400 square kilometers of territory in four days. After nine days of high-intensity combat, and the destruction by the SS of two-thirds of Soviet tanks in the entire 3rd Ukrainian Front, the German offensive wa