The year 1956 was pivotal in the Khrushchev period. Khrushchev was born on 15 April 1894 in the poor southern Russian village of Kalinovka, and his childhood there profoundly shaped his character. During the 1930s and 1940s, Khrushchev played a central role in Stalinism. His positive contributions included supervising construction of the Moscow metro, energising Ukrainian agriculture and industry after the Great Purges, and attempting to ameliorate the post-war famine which Joseph Stalin's draconian policies caused. Khrushchev's first priority was agriculture. Khrushchev's 1955 journey to Belgrade reflected a new, post-Stalinist formula for holding together the Soviet bloc: to tolerate a modicum of diversity and domestic autonomy, to emphasise ideological and political bonds and reinforce economic and political ties, and to weave all this together with Khrushchev's own personal involvement. Khrushchev's first major achievement was the Austrian State Treaty, signed in May 1955, under which Soviet occupation forces pulled out in return for an Austrian declaration of neutrality.