The unit fought at the Battle of Lenino (September 1943) and at the Battle of Studzianki during the Lublin-Brest Offensive (Magnuszew bridegheads in August 1944). From mid-August it was subordinate to the Polish First Army. Later the unit fought in the East Pomeranian Offensive. In January 1945 it received another the honorary name, Warszawska (of Warsaw). In July and August 1945 fought against Polish anti-Communist guerilla. In January 1946 it was downsized to regiment (becoming 1st Warsaw Tank Regiment), and from June it was stationed in the Modlin area.