The Soviets made sure that a loyal post-war government dominated by Communists was installed in the country before transferring authority from the occupational force to the Hungarian authorities. The presence of Soviet troops in the country was regulated by the 1949 mutual assistance treaty concluded between the Soviet and Hungarian governments. The Hungarian Revolution of 1956 was a spontaneous nationwide revolt against the Communist government of Hungary and its Soviet-imposed policies. After announcing a willingness to negotiate the withdrawal of Soviet forces, the Soviet Politburo changed its mind. On 4 November 1956, a large joint military force of the Warsaw Pact led by Moscow, entered Budapest to crush the armed resistance, killing thousands of civilians in the process.