Relations between Hungary and Romania were officially established on 21 August 1920 in the current form, but the two countries have a long mutual history dating back to the Middle Ages. Transylvania, today entirely situated within the borders of Romania, has been a subject of animosity between the two states, having previously been part of the Kingdom of Hungary for centuries.

The countries share a border stretching for about 440 kilometers, which was fixed after the Treaty of Trianon and has not suffered serious modifications since, except during WWII. In the present day, the border is opened as a result of the Schengen Area to which both Hungary and Romania belong, as an extension of being European Union member states. They are also both part of NATO and various other economic and political groups, such as the Southeast European Cooperation Initiative.

As of 2026, the two nations are close on a political and economic level, though in recent years there have been of instances of tensions arising due to historical factors. Hungarians represent the biggest ethnic minority of Romania, accounting for almost 7% of Romania's entire population.

History

Transylvania, a region of great cultural importance for both Romania and Hungary due to its history and ethnic composition, remains the focal point of tension between the two countries. This region is central to debates over cultural identity, minority rights and competing historical claims.

In Antiquity, Transylvania was part of the Dacian Kingdom, which was later conquered by Roman Emperor Trajan through the Dacian Wars, culminating in 106 AD. The region became a Roman Province, witnessing urbanization, the spread of Latin influence, and significant economic development. However, the province of Roman Dacia remained vulnerable and, by 271–275 AD, Rome abandoned it in the face of relentless barbarian invasions. Whether a Romanized population remained in the region is a topic of debate among historians.

As the Roman legions withdrew, a period of turmoil and migration ensued. Goths, Huns, Gepids, and Avars each left their mark on this region in the following centuries. Slavs began settling in Transylvania around the 7th century and left traces up to the end of the 12th century. During the 9th century, the First Bulgarian Empire extended its control over parts of Transylvania. The Magyar tribes occupied the Carpathian Basin around 895 AD, with evidence of their settlement in Transylvania dating to the first half of the 10th century, as proven by archaeological artifacts.Fine, Jr., John V. A. (1994). The Early Medieval Balkans – A Critical Survey from the Sixth to the Late Twelfth Century. The University of Michigan Press. p. 139. The Gesta Hungarorum, the first Hungarian historical chronicle, written around 1200, claims that Transylvania was inhabited by Vlachs (Romanians) and Slavs during the Hungarian conquest. However, the reliability of this work is contested by some historians. Transylvania eventually became part of the Hungarian Kingdom in 1003, when King Stephen I of Hungary defeated its ruler, Gyula III, a local chieftain who controlled the region. Early documents about Transylvania make passing references to both Hungarians and Vlachs (Romanians), with the first official royal charter mentioning the latter in 1223. Hungarian historians claim the migration of Vlachs from the Balkans started around this period, meanwhile Romanian historians argue that their presence is linked to the continuity of the Romanized population of Dacia.

Throughout the medieval era, Transylvania maintained a unique status within the Hungarian Crown, governed by its own voivode and characterized by a tripartite ethnic and social structure comprising Hungarians, Saxons, and Szeklers, called the Unio Trium Nationum, with Romanians largely denied the privileges afforded to the other groups and confined to a lower social and economic position. In 1526, after the Battle of Mohács, Transylvania became part of the Eastern Hungarian Kingdom. The Principality of Transylvania emerged from this entity in 1570 through the Treaty of Speyer. During much of the 16th and 17th centuries, the principality existed as a vassal state of the Ottoman Empire, though it maintained a unique dual suzerainty, recognizing both the Ottoman Sultan and the Habsburg kings of Hungary as overlords.Dennis P. Hupchick, Conflict and chaos in Eastern Europe, Palgrave Macmillan, 1995, p. 62Peter F. Sugar, Southeastern Europe under Ottoman rule, 1354–1804, University of Washington Press, 1993, pp. 150–154 Wallachian ruler Michael the Brave briefly ruled Wallachia, Moldova, and Transylvania simultaneously for less than a year, from November 1599 until his death in September 1600. Transylvania's religious diversity grew in the wake of the Protestant Reformation, as Lutheran, Calvinist, and Unitarian movements took hold alongside Catholicism and Orthodox Christianity. Rulers such as John Sigismund and Gabriel Bethlen fostered religious tolerance and cultural development, making Transylvania a beacon of multi-confessional harmony in early modern Europe.

With the defeat of the Ottomans at the Battle of Vienna in 1683, the Habsburg monarchy gradually began to impose their rule on the formerly autonomous Transylvania. From 1711 onward, after the conclusion of Rákóczi's War for Independence, Habsburg control over Transylvania was consolidated, and the princes of Transylvania were replaced with Habsburg imperial governors. In 1765 the Grand Principality of Transylvania was proclaimed, consolidating the special separate status of Transylvania within the Habsburg Empire, established by the Diploma Leopoldinum in 1691. The Hungarian historiography sees this as a mere formality. Within the Habsburg Empire, Transylvania was administratively part of Kingdom of Hungary. The Romanian peasants, particularly, faced social and economic discrimination during this period, which led to uprisings like the Revolt of Horea, Cloșca, and Crișan in 1784. The Supplex Libellus Valachorum of 1791 marked an important step in the Romanian national movement, laying the groundwork for future struggles for equality and autonomy.

Throughout the 19th century, Transylvania was a focal point of nationalist movements, for both Hungarians and Romanians. During the Hungarian Revolution of 1848, both groups fought for their national aspirations, but their divergent goals escalated into direct conflict.Hermann Róbert: Magyarország története 14. Kossuth Kiadó, 2009 Budapest, p. 38 Hungarians, led by Lajos Kossuth, sought independence from the Habsburg Empire and viewed Transylvania as part of a centralized Hungarian state. Romanians, meanwhile, led by Avram Iancu, demanded equality, the abolition of feudal privileges and recognition of their language. The conflict deepened ethnic divisions between the two communities, as numerous massacres took place in Transylvania during that time. The Habsburgs initially supported the Romanians to weaken the Hungarian Revolution but abandoned them after crushing the uprising in 1849 with Russian help. After the Austro-Hungarian Compromise of 1867, Transylvania was fully incorporated into the Kingdom of Hungary. This also marked the beginning of Magyarization policies in Transylvania.

In 1880, according to the official census, Transylvania had around 4 million inhabitants, of which 57.0% were Romanians, 25.9% Hungarians and 12.5% Germans.Árpád Varga E., Hungarians in Transylvania between 1870 and 1995, Original title: Erdély magyar népessége 1870–1995 között, Magyar Kisebbség 3–4, 1998 (New series IV), pp. 331–407. Translation by Tamás Sályi, Teleki László Foundation, Budapest, 1999 After the Unification of Wallachia and Moldavia in 1859, the newly formed Romanian Kingdom began to actively pursue the goal of incorporating Transylvania, which was deeply tied to the region's Romanian-majority population. This aspiration significantly influenced Romania's position during World War I. Initially neutral, Romania joined the Triple Entente in 1916, motivated by the promise of territorial gains, including Transylvania, as outlined in the secret Treaty of Bucharest signed that year. Although Romania's military campaign faced setbacks, including a temporary occupation by the Central Powers, the eventual collapse of Austria-Hungary in 1918 created the opportunity for the Union of Transylvania, Banat, Crișana and Maramureș with Romania, as proclaimed on 1 December 1918. This was met with resistance from Hungary, leading to the Hungarian–Romanian War of 1919. The newly proclaimed Hungarian Soviet Republic, led by Béla Kun, sought to reclaim territories lost during World War I. After a series of battles, the Romanian forces advanced deep into Hungary, eventually capturing Budapest in August 1919. This marked the end of the Hungarian Soviet Republic and solidified Romania's control over Transylvania.

The war concluded with the Treaty of Trianon in 1920, which formally recognized the union of Transylvania with Romania. However, the conflict left a legacy of tension between Hungary and Romania, as Hungary viewed the loss of Transylvania as a profound injustice, while Romania viewed the unification with Transylvania as a legitimate integration of Romanian-majority lands. More than 1.5 million Hungarian minority of Transylvania found itself becoming a minority group within Romania.Kovrig, Bennett (2000), Partitioned nation: Hungarian minorities in Central Europe, in: Michael Mandelbaum (ed.), The new European Diasporas: National Minorities and Conflict in Eastern Europe, New York: Council on Foreign Relations Press, pp. 19–80. Also after World War I, a group of Csángó families founded a village in Northern Dobruja known as Oituz, where Hungarians still live today.

In August 1940, during the Second World War, the northern half of Transylvania was returned to Hungary by the second Second Vienna Award. Historian Keith HitchinsHitchins, Keith (1994), Rumania: 1866–1947 (Oxford History of Modern Europe). Oxford University Press summarizes the situation created by the award: Some 1,150,000 to 1,300,000 Romanians, or 48 per cent to over 50 per cent of the population of the ceded territory, depending upon whose statistics are used, remained north of the new frontier, while about 500,000 Hungarians (other Hungarian estimates go as high as 800,000, Romanian as low as 363,000) continued to reside in the south. The Treaty of Paris (1947) after the end of the Second World War overturned the Vienna Award, and the territory of northern Transylvania was returned to Romania. The post-World War II borders with Hungary agreed on at the Treaty of Paris were identical with those set out in 1920. After the war, in 1952, a Magyar Autonomous Region was created in Romania by the communist authorities. The region was dissolved in 1968, when a new administrative organization of the country (still in effect today) replaced regions with counties. The communist authorities, and especially after Nicolae Ceaușescu's regime came to power, restarted the policy of Romanianization. Today, "Transylvania proper" (bright yellow on the accompanying map) is included within the Romanian counties (județe) of Alba, Bistrița-Năsăud, Brașov, Cluj, Covasna, Harghita, Hunedoara, Mureș, Sălaj (partially) and Sibiu. In addition to "Transylvania proper", modern Transylvania includes Crișana and part of the Banat; these regions (dark yellow on the map) are in the counties of Arad, Bihor, Caraș-Severin, Maramureș, Sălaj (partially), Satu Mare, and Timiș.

Conflicts

World War I