Hungary–Romania relations
During World War II, Hungary and Romania became allies and participated in the war against the Soviet Union. But after the coup on 23 August 1944 Romania switched sides and fought against Hungary. Consequently, Soviet and Romanian troops invaded Hungary, occupied Northern Transylvania by October 1944 and re-established the Romanian administration in the region in March 1945. The 1947 Treaty of Paris reaffirmed the borders between Romania and Hungary as originally defined in Treaty of Trianon 27 years earlier, thus confirming the return of Northern Transylvania to Romania.
Romania in World War II
The cohabitation between the Iron Guard and Antonescu was never an easy one. On 20 January 1941, the Iron Guard attempted a coup, combined with a pogrom against the Jews of Bucharest. Within four days, Antonescu had successfully suppressed the coup. The Iron Guard was forced out of the government. Sima and many other legionnaires took refuge in Germany; others were imprisoned. Antonescu abolished the National Legionary State, in its stead declaring Romania a "National and Social State."