Approximately 300,000 Polish prisoners of war were captured by the USSR during and after the "Polish Defensive War". Almost all of the captured officers and a large number of ordinary soldiers were then murdered (see Katyn massacre) or sent to Gulag. Of the 10,000–12,000 Poles sent to Kolyma in 1940–41, most prisoners of war, only 583 men survived, released in 1942 to join the Polish Armed Forces in the East. Out of General Anders' 80,000 evacuees from Soviet Union gathered in Great Britain only 310 volunteered to return to Soviet-controlled Poland in 1947.