Two armies were formed separately and at different times. "Anders' Army", created in the second half of 1941, was loyal to the Polish government-in-exile. After Operation Barbarossa and the consequent Polish-Soviet Sikorski–Mayski agreement, an amnesty for Polish citizens in the Soviet Union was declared, which made the formation of Polish military units possible.&lt;ref name="https://direct.mit.edu/isec/article/46/1/147/102854/Leaning-on-Legionnaires-Why-Modern-States-Recruit"&gt;&lt;/ref&gt; In 1942, Anders' Army was evacuated to Iran and transferred to the command of the Western Allies. It became known as the Polish II Corps and went on to fight Nazi German forces in the Italian Campaign, including the Battle of Monte Cassino.