Wiener Operation
On 29 March 1945, Soviet commander Fyodor Tolbukhin's troops crossed the former Austrian border at Klostermarienberg in Burgenland. On 3 April, at the beginning of the Vienna Offensive, Renner, then living in southern Lower Austria, established contact with the Soviets. Joseph Stalin had already established a would-be future Austrian cabinet from the country's communists in exile, but Tolbukhin's telegram changed Stalin's mind in favor of Renner.