The Hungarian–Romanian War (Hungarian: magyar–román háború; Romanian: războiul româno-ungar) was fought between Hungary and Romania from 13 November 1918 to 3 August 1919. The conflict had a complex background, with often contradictory motivations for the parties involved.
Compared with the vast mobilizations of the First World War, both sides fielded remarkably small armies, and the proportion of deaths remained extraordinarily low throughout the fighting: During the entire nine-month campaign cost the Romanians just 3,670 killed, meanwhile Hungarian KIA is widely estimated between 2.000 to 6.000 soldiers.
After the unilateral self-disarmament of the Hungarian army by the pacifist Hungarian prime minister Count Mihály Károlyi, the Allies of World War I intended that Romania's Army, the Czechoslovak army and the Franco-Serbian armies to occupy various parts of Kingdom of Hungary. At the same time, there was a reluctance to allow Romania to occupy Hungary fully, although their intention was to, at least in part, satisfy the Romanian claims in accordance with the Treaty of Bucharest (1916) which proposed that Hungary cede Transylvania, Partium and parts of Banat to Romania. The situation was further complicated by the strained relationship between the Romanian delegation at the Paris Peace Conference and the Great Powers. France, in particular, was keen on the participation of Romania in the intervention against the Bolshevik forces in Russia while the Romanian authorities conditioned this involvement on the fulfillment of the promises made by the Allies in 1916. Some Allied leaders in Paris supported the advance of the Romanian Army while the Council of Four withheld its approval of the military actions. The French General Staff encouraged a continued Romanian advance to Budapest, with Generals Ferdinand Foch, Louis Franchet d'Espèrey, and Henri Mathias Berthelot particularly in favor of this approach.
In Transylvania there were political and ethnic tensions between various Romanian, Hungarian, Saxon, and other ethnic groups. However, Romania's motivations to enter the neutral zone and cross the demarcation lines were not limited only to protecting the ethnic Romanians, but also to occupy the territory in accordance with the 1916 agreement, thus presenting the Allies with a fait accompli.
In the aftermath of World War I and the proclamation of the independence of Hungary from the Dual Monarchy, the Hungarians tried to convince the Allies that "Hungary should not be penalized too harshly for the sins of the old". Despite the Hungarian government offering concessions to the ethnic minorities, it was "too little, too late". The political leaders of ethnic Romanians, as well as Serbs, Slovaks, Croats, and other minorities, had already decided to secede. Moreover, the decision of the Council of Four to establish a neutral zone that largely reflected the treaty between Romania and the Allies in 1916 contributed to the liberal president Count Mihály Károlyi's resignation and the subsequent creation of the Hungarian Soviet Republic. The threat of Béla Kun's Hungarian Red Army and Red Guards linking up with other Bolshevik forces was decisive in the joint decision of several Allied representatives and the Romanian authorities to "settle the Hungarian question immediately".
Background
Postwar Hungary
Aster Revolution, liberal republic and self-disarmament of Hungary
In 1918, Austria-Hungary collapsed politically and disintegrated as a result of its defeat on the Italian Front. During the war, the liberal Hungarian aristocrat Count Mihály Károlyi had led a small but very active pacifist antiwar maverick faction in the Hungarian Parliament. He had even organised covert contacts with British and French diplomats in Switzerland during the war. On 31 October 1918, the Aster Revolution in Budapest brought to power Károlyi, a supporter of the Allies. The Hungarian Royal Honvéd army still consisted of 1,400,000 soldiers, who had been recruited from the territory of Kingdom of Hungary when Mihály Károlyi was announced as Hungarian prime minister. Károlyi yielded to US President Woodrow Wilson's demand for pacifism by ordering the disarmament of the Hungarian Army, which happened under the direction of War Minister Béla Linder on 2 November 1918. The unilateral disarmament of its army made Hungary remain without national defence. Thus it became particularly vulnerable. Oszkár Jászi, the new Minister for National Minorities of Hungary, offered referendums on the disputed borders for minorities (such as the Romanians in Transylvania), but the political leaders of those minorities refused the very idea of referendums regarding disputed territories at the Paris Peace Conference.
International reactions after Hungarian unilateral disarmament
Six days later, on 5 November 1918, the Serbian Army, with the help of the French Army, crossed the southern border of the Kingdom of Hungary. On 8 November, the Czechoslovak Army crossed the northern border, and on 13 November, the Romanian Army crossed the eastern border. That day, Károlyi signed an armistice with the Allies in Belgrade, which limited the size of the Hungarian Army to six infantry and two cavalry divisions. Demarcation lines defining the territory to remain under Hungarian control were made.
The lines would apply until definitive borders could be established. Under the terms of the armistice, Serbian and French troops advanced from the south and took control of the Banat and Croatia. Czechoslovakia took control of Upper Hungary (today mostly Slovakia) and Carpathian Ruthenia. Romanian forces were permitted to advance to the Mureș River. However, on 14 November, Serbia occupied Pécs. The Hungarian unilateral disarmament made the occupation of Hungary possible for the relatively small Romanian Army, Franco-Serbian army and the armed forces of the newly-established Czechoslovakia. During the rule of Károlyi's pacifist cabinet, Hungary lost control of approximately 75% of its former prewar territories (325,411 km2 (125,642 sq mi) .
Romania during the First World War
Proclamation of King Ferdinand I of Romania to the Romanian People, 28 August 1916:
"In our moral energy and our valour lie the means of giving him back his birthright of a great and free Rumania from the Tisza to the Black Sea, and to prosper in peace in accordance with our customs and our hopes and dreams."
On August 27, 1916, the Kingdom of Romania declared war against Austria-Hungary and entered the First World War on the side of the Allies. In doing so, Romania's goal was to unite all the territories in which a Romanian population existed in a single state. In the Treaty of Bucharest of August 17, 1916, terms for Romania's acquisition of territories in Austria-Hungary were stipulated. However, in military and geopolitical sense, the key factor in Romania's entry into the war was the successes of the Russian Brusilov offensive against Austria-Hungary. After a short Romanian initial success, the campaign turned into a military disaster for Romania.
After three months of war, two thirds of the territory of the Kingdom of Romania were occupied by the Central Powers. Bucharest, the capital city of Romania, was captured by the Central Powers on 6 December 1916. German General August von Mackensen was appointed as the "military governor" of the occupied territories of Romania. Following Russia's ceasefire agreements, the Romanian army was forced to sign the Armistice of Focșani on 9 December 1917.
In 1918, after the October Revolution, the Bolsheviks signed a separate peace with the Central Powers in the Treaty of Brest-Litovsk. Romania was alone on the Eastern Front, a situation that far surpassed its military capabilities. Therefore, on 7 May 1918, Romania sued for peace. Romanian Prime Minister Alexandru Marghiloman signed the Treaty of Bucharest (1918) with the Central Powers, but the treaty was never signed by King Ferdinand I of Romania.
At the end of 1918, Romania's situation was dire. It was suffering from the consequences of punitive war reparations. Dobruja was under Bulgarian occupation. The bulk of the Romanian Army was demobilised and had only four full-strength divisions. A further eight divisions were left in a reserve status. Only the 9th and 10th infantry divisions and the 1st and 2nd cavalry divisions were at full strength. However, those units were engaged in the protection of Bessarabia against Soviet Russia.
On 11 November 1918, Germany signed an armistice with Allies under which they had to immediately withdraw all German troops in Romania and in the Ottoman Empire, the Austro-Hungarian Empire and the Russian Empire back to German territory. The Allies were to have access to those countries. After the German armistice, the units of the German Army, under the command of Marshal August von Mackensen, were ordered to retreat to Germany.
November 1918 – March 1919
On 10 November 1918, less than 24 hrs. before the war's end, Romania re-entered the war on the side of the Allied forces, with similar objectives to those of 1916. King Ferdinand called for the mobilisation of the Romanian Army and ordered it to attack by crossing the Carpathian Mountains into Transylvania. The 1st Vânători and the 7th and 8th Infantry divisions, stationed in Moldavia, were the first units to be mobilised. The 8th was sent to Bukovina and the other two were sent to Transylvania. On 13 November, the 7th entered Transylvania at the Prisăcani River in the Eastern Carpathians. The 1st then entered Transylvania at Palanca, Bacău.
On 1 December, the desire of the Union of "Transylvania, Banat and the Hungarian Lands" with Romania was declared by the 1,228 elected representatives of the Romanian people of Transylvania, Banat, Crișana and Maramureș, who proclaimed the union with Romania. Later, the Transylvanian Saxons and Banat Swabians also supported the union. On 7 December, Brașov was occupied by the Romanian Army. Later that month, Romanian units reached the line of the Mureș River, a demarcation line that had been agreed upon by the representatives of the Allies and Hungary at the Armistice of Belgrade.
Following a request from Romania, the Allied Command in the east, led by French General Louis Franchet d'Espèrey, allowed the Romanian Army to advance to the line of the western Carpathians. The 7th Infantry division advanced toward Cluj, and the 1st division advanced in toward Alba Iulia. On 24 December, units of the Romanian Army entered Cluj-Napoca. By 22 January 1919, the Romanian army controlled all the territory to the Mureș River. The 7th and 1st divisions were spread thinly and so the 2nd Division was sent to Sibiu and the 6th Division to Brașov. Two new infantry divisions, the 16th and 18th, were formed from soldiers previously mobilised in the Austro-Hungarian Army. A unified command of the Romanian Army in Transylvania was established. Its headquarters were at Sibiu, with General Traian Moșoiu in command. Although Romania controlled new territories, it did not encompass all ethnic Romanians in the region.
On 28 February 1919, at the Paris Peace Conference, the Allies notified Hungary of a new demarcation line to which the Romanian army would advance. The line coincided with railways connecting Satu Mare, Oradea, and Arad. However, the Romanian Army was not to enter those cities. A demilitarised zone was to be created extending from the new demarcation line to 5 kilometres (3.1 mi) beyond the line. The demilitarised zone represented the extent of Romanian territorial requests on Hungary. The retreat of the Hungarian Army behind the western border of the demilitarised zone was to begin on 22 March.
On 19 March, Hungary received notification of the new demarcation line and demilitaritarised zone from French Lieutenant Colonel Fernand Vix (the "Vix Note"). The Károlyi government would not accept the terms, which was a trigger for the coup d'état by Béla Kun, who formed the Hungarian Soviet Republic. Meanwhile, limited sporadic skirmishes took place between Romanian army and small local Hungarian civil insurgent groups. Some Hungarian elements engaged in the harassing the Romanians outside the area controlled by the Romanian Army.
Interventions, fall of liberal regime and communist coup
The pacifist Károlyi government failed to manage domestic and military issues and lost popular support. On 20 March 1919, Béla Kun, who had been imprisoned in the Markó Street prison, was released. On 21 March, he led a successful communist coup d'état. President Károlyi was deposed and arrested by the new government. Kun formed a social democratic communist coalition government and proclaimed the Hungarian Soviet Republic. Days later, the communists purged the Social Democrats from the government. The Hungarian Soviet Republic was a small communist rump state. When the Republic of Councils in Hungary was established, it controlled only approximately 23% of the Hungary's historic territory.
The communists remained bitterly unpopular in the Hungarian countryside, where the authority of that government was often nonexistent. The communist had real popular support only among the proletarian masses of large industrial centres, especially in Budapest, where the working class represented a high proportion of the population. The communist government followed the soviet model. The party established its terror groups (like the infamous Lenin Boys) to "overcome the obstacles" in the Hungarian countryside, which was later known as the Red Terror in Hungary.
The new government promised equality and social justice. It proposed that Hungary be restructured as a federation. The proposal was designed to appeal to both domestic and foreign opinion. Domestic considerations included maintaining the territorial integrity and economic unity of former crown lands and protecting the nation's borders. The government had popular support in the cities and the support of the army. Most of the officers in the Hungarian Army came from regions that had been forcibly occupied during the First World War, which heightened their patriotic mood. Hungary as a federation would appeal to Wilson under his doctrine of self-determination of peoples because of the nation's multiethnic composition. In addition, self-governed and self-directed institutions for the non-Magyar peoples of Hungary would lessen the dominance of the Magyar people.
April–June 1919
After 21 March 1919, Romania found itself between two nations with communist governments: Hungary to the west and Soviet Russia to the east. The Romanian delegation at the Paris Peace Conference asked the Romanian Army to be allowed to oust Kun's communist government in Hungary. The Allies were aware of the communist danger to Romania. However, there was a climate of dissension in the council among United States President Woodrow Wilson, British Prime Minister David Lloyd George, and French Prime Minister Georges Clemenceau about guarantees required by France on its borders with Germany. In particular, the American delegation was convinced that French hardliners around Marshal Ferdinand Foch were trying to initiate a new conflict with Germany and Soviet Russia. The Allied council tried to defuse the situation between Romania and Hungary.