August 1944, and therefore "acted in the interests of all the United Nations". As a reward, Northern Transylvania was, once again, recognized as an integral part of Romania, but the border with the USSR and Bulgaria was fixed at its state in January 1941, restoring the pre-Barbarossa status quo (with one exception). Following the dissolution of the Soviet Union in 1991, the Eastern territories became part of Ukraine and the Republic of Moldova. In Romania proper, Soviet occupation following World War II facilitated the rise of the Communist Party as the main political force, leading ultimately to the forced abdication of the King and the establishment of a single-party people's republic in 1947. Communist period (1947–1989) Soviet occupation following World War II strengthened the position of Communists, who became dominant in the left-wing coalition government that was appointed in March 1945. King Michael I was forced to abdicate and went into exile. Romania was proclaimed a people's republic and remained under military and economic control of the Soviet Union until the late 1950s. During this period, Romania's resources were drained by the "SovRom" agreements; mixed Soviet-Romanian companies were established to mask the Soviet Union's looting of Romania. Romania's leader from 1948 to his death in 1965 was Gheorghe Gheorghiu-Dej, the First Secretary of the Romanian Workers' Party. The Communist regime was formalized with the constitution of 13 April 1948. On 11 June 1948, all banks and large businesses were nationalized. This started the process of the Romanian Communist Party to collectivize the country's resources including agriculture. In 1946 and 1947, several high-ranking members in the pro-Axis government were executed as war criminals, primarily for their involvement in the Holocaust and for attacking the Soviet Union. Antonescu himself was executed 1 June 1946. Once the Communist government became more entrenched, the number of arrests increased. All strata of society were involved, but particularly targeted were the prewar elites, such as intellectuals, and anybody who could potentially form the nucleus of anti-Communist resistance. According to figures, in the years between 1945 and 1964, 73,334 people were arrested. Between 60,000 and 80,000 political prisoners were detained. Gheorghiu-Dej attained greater independence for Romania from the Soviet Union by persuading Soviet First Secretary Nikita Khrushchev to withdraw troops from Romania in April 1958. After the negotiated withdrawal of Soviet troops, Romania under the new leadership of Nicolae Ceauşescu started to pursue independent policies, including the