[2] From October 12 to 14, 1943, the First Polish Infantry Division made an assault on Lenino near Smolensk and sustained twenty-five percent losses.

After eventually taking control of Warsaw in January 1945, the First Army took part in the Vistula–Oder Offensive, and afterwards it moved towards Bydgoszcz.

[5] In the spring of 1945 the army, now numbering 78,556 soldiers, was redeployed to the front on the Oder river in preparation for the final Soviet offensive of the war in Europe.

In this, among other actions, Polish units of the 1st Army crossed the Hohenzollern Canal and advanced on Kremmen, Flatow, Paaren and Nauen.

[10] Its constituent units went on to serve in the armed forces of the newly created Polish People's Republic.

[citation needed] It had a good mix of infantry units and artillery together with other support arms.

[6] At the end of the war in 1945, it consisted of the following large units (honorific names given in brackets)[12] Organization as of May 1, 1945