The Dnieper–Carpathian offensive, also known in Soviet historical sources as the liberation of right-bank Ukraine, was a strategic offensive executed by the Soviet 1st, 2nd, 3rd, and 4th Ukrainian Fronts, along with the 2nd Belorussian Front, against the German Army Group South, Army Group A and elements of Army Group Center, and fought from late December 1943 to early May 1944. Wikipedia