Hungary–Romania relations

Export and import from Hungary to Romania[13] [14]

Million (€)	2012	2013	2014	2015	..	2017
Export	4,767.23	4,600.36	4,609.39	4,742.39	..	5,600.00
Import	2,050.98	2,120	2,500.07	2,550.72	..	2,900.00
Balance	2,716.25	2,480.34	2,109.32	2,191.68	..	2,700.68

Most important Hungarian investors in Romania: MOL, OTP Bank, Gedeon Richter Plc.

Most important Romanian investors in Hungary: RCS & RDS, Automobile Dacia.

During the war, initially the Kingdom of Romania was neutral to the Central Powers, thus with Austria-Hungary. In August 1916 Romania entered the war on side of the Allies and attacked the Kingdom of Hungary, however it was pushed back to the frontier in October and by January 1917, two-thirds of Romania were occupied by the Central Powers. The Romanians were forced to retreat to the historical region of Moldavia, but were able to stave off complete collapse in 1917 by reorganizing their army and repulsing the Central Powers' offensive at Mărășești and Oituz. Nevertheless, after the October Revolution of 1917, Russia fell into civil war, and the Russian government signed two ceasefire agreements with the Central Powers, followed later (on December 15) by a full armistice. Lacking Russian support, the Romanian government was subsequently forced to sue for peace, concluding in December 1917 the Armistice of Focșani.

In 1918, Romania re-entered the war with similar objectives to those of 1916. During the 1919 Hungarian–Romanian War Hungary, led by Communist forces, tried to secure its borders, however it was soon defeated and later occupied by Romanian forces for a few months' time.

The Treaty of Trianon was the peace agreement of 1920 that formally ended World War I between most of the Allies (among them the Kingdom of Romania) and the Kingdom of Hungary, the latter being one of the successor states to Austria-Hungary. As a result of the treaty the regions of Transylvania, parts of the Banat, Crișana and Maramureș became part of the Kingdom of Romania.

The Treaty of Trianon and its consequences dominated Hungarian public life and political culture in the inter-war period. Moreover, the Hungarian government swung then more and more to the right; eventually, under Regent Miklós Horthy, Hungary established close relations with Benito Mussolini's Fascist Italy and Adolf Hitler's Nazi Germany. These politics and the sought for revision succeeded to regain the territories of southern Czechoslovakia by the First Vienna Award in 1938 and the annexation of the remainder of Subcarpathia in 1939. These were only a fraction of the territories lost by the Treaty of Trianon, anyway the loss that the Hungarians resented the most was that of Transylvania ceded to the Romanians.

In 1940, the Soviet occupation of Bessarabia and Northern Bukovina inspired Hungary to escalate its efforts to resolve "the question of Transylvania". Hungary hoped to gain as much of Transylvania as possible, but the Romanians submitted only a small region for consideration. Eventually, the Hungarian-Romanian negotiations fell through entirely. After this, the Romanian government asked Italy and Germany to arbitrate. Foreign Ministers Joachim von Ribbentrop of Germany and Galeazzo Ciano of Italy met on 30 August 1940 at the Belvedere Palace in Vienna and decided that Romania cede Northern Transylvania, with an area of 43,104 km² (16,643 sq mi) and a population of 2,577,260, out of which, according to the Romanian estimates, 1,304,903 were Romanians (50.2%) and 978,074 (37.1%) Hungarians,[15] or, according to the Hungarian census of 1941, 53.5% were Hungarians and 39.1% Romanians.[16]

In 1940 ethnic disturbances between Hungarians and Romanians continued after some incidents following the occupation of Northern Transylvania by the Hungarian military, culminating in massacres at Treznea and Ip. After some ethnic Hungarian groups considered unreliable or insecure were sacked/expelled from Southern Transylvania, the Hungarian officials also regularly expelled some Romanian groups from Northern Transylvania. Also, many Hungarians and Romanians fled or chose to opt between the two countries. There was a mass exodus; over 100,000 people on both sides of the ethnic and political borders relocated.[17]

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.