By July 1945 there were 228,000 troops of the Polish Armed Forces in the West serving under the British. Many of these men and women came from the "Kresy" region (eastern Poland), including from the major cities of Lwów (now Lviv, Ukraine) and Wilno (now Vilnius, Lithuania). They had been deported by the Soviets from the "Kresy" to the gulags when Nazi Germany and the Soviet Union occupied Poland in 1939 under the Nazi-Soviet Pact. Two years later, when Churchill and Joseph Stalin formed an alliance against Adolf Hitler, the mostly ""Kresy" Poles" were released from the Gulags in Siberia to form "Anders' Army" and were made to walk via Khazakstan, Uzbekistan and Turkmenistan, where thousands perished on the way, to Iran. There the Polish II Corps came into being under British command. They fought in the battles of Monte Cassino, the Falaise Gap, Arnhem, Tobruk, and in the liberation of many European cities, including Bologna and Breda.