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.
List of Romanian-built warships of World War II
In 1907, despite lacking a dry dock, the Romanian shipyard at Galați was able to co-build a class of four 700-ton river monitors for the Romanian Danube Flotilla: the "Mihail Kogălniceanu" class. The four vessels of this class were built in sections at STT in Austria-Hungary, transported to Romania then assembled and launched at Galați. Each monitor had an overall armour thickness of 70-75 mm. During World War II, all four monitors were fitted for service at sea as anti-submarine escorts, each being armed with three 120 mm naval guns in single armored turrets, one 76 mm naval/AA gun, two 47 mm naval guns and two depth charge throwers (one of 760 mm and the other of 700 mm). The four warships were in service throughout both world wars. "Mihail Kogălniceanu" engaged in battle and damaged two Soviet river monitors during the first month of "Operation Barbarossa". She also shot down one Soviet aircraft on 29 June 1941.