Stalin then severed relations with the Polish government in exile . Since it was clear that it would be the Soviet Union , not the western Allies , who would liberate Poland from the Germans , this breach had fateful consequences for Poland . In an unfortunate coincidence , Sikorski , widely regarded as the most capable of the Polish exile leaders , was killed in an air crash at Gibraltar in July 1943 . He was succeeded as head of the Polish government in exile by Stanisław Mikołajczyk
killed in an air crash
1943 Gibraltar B-24 crash
Polish government-in-exile