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.
Former administrative divisions of Romania
This territory was administered by Romania briefly in 1941-1944, when the country was governed by a military dictatorship allied with Nazi Germany. It consisted of formerly proper Soviet territory between Dniester and Southern Bug rivers. Nowadays, most of it is in Ukraine, with small parts in the Republic of Moldova (Transnistria). This territory was kept under Romanian military occupation, and was not annexed by Romania. It was divided into 13 counties:In 1913, as a result of the Second Balkan War, Romania acquired Southern Dobruja from Bulgaria, annexing this historical region within Romania's borders. In 1940, Nazi Germany and Fascist Italy forced Romania to return it to Bulgaria ("see Treaty of Craiova"). Romania did not reclaim this area neither after the end of World War II nor at the fall of communism.