In the immediate aftermath of World War I, the region of Međimurje was occupied by forces loyal to the National Council of the State of Slovenes, Croats and Serbs, one of the predecessor states to the Kingdom of Yugoslavia, in November and December 1918. Predominantly inhabited by Croats, this territory was a part of the Kingdom of Hungary until it was captured by Yugoslav forces. The Paris Peace Conference (1919–1920) awarded the region to Yugoslavia, which annexed the territory.
The campaign to capture Međimurje began in November 1918, ostensibly in response to Hungarian actions against a revolt by the population of Međimurje. Major Ivan Tomašević led a 300-strong force that was routed by Hungarian forces near Čakovec, the region's largest town. Pleas for military help from the Royal Serbian Army and the French Armée d'Orient were rebuffed due to obligations assumed under the Armistice of Belgrade between the Entente Powers and Hungary that defined the Drava River as the line of Hungarian control in the area. The National Council mounted a new effort on 24 December, sending a 3,000-strong force made up by Slovene volunteers and much of the Royal Croatian Home Guard. Major Dragutin Perko planned the second incursion into Međimurje in greater detail, and he later commanded a large part of the attacking forces.
Međimurje was captured on 24 December without resistance from the Hungarian garrison. Perko was appointed its administrator, and the region was declared a part of the Kingdom of Serbs, Croats and Slovenes with a reference to the principle of self-determination. The Paris Peace Conference later confirmed the region's accession.
Background On 5–6 October 1918, representatives of political parties representing Slovenes, Croats, and Serbs living in Austria-Hungary organised the National Council of Slovenes, Croats and Serbs as the central organ of the newly proclaimed State of Slovenes, Croats and Serbs encompassing the Slovene Lands, Croatia-Slavonia, Dalmatia, and Bosnia and Herzegovina. The council supplanted the previously established ad hoc group known as the Yugoslav Committee as the body representing the interests of the South Slavs living in Habsburg lands. Its original objective was to campaign for independence of the South Slavs from Austria-Hungary and the unification of those lands with the Serbia, according to Yugoslavism. Serbia had stated its World War I objective of unification of these lands in its 1914 Niš Declaration.
On 29 October, the Sabor of Croatia-Slavonia declared independence from Austria-Hungary. The council met with Serbian representatives in Geneva, Switzerland, in early November and accepted Serbian Prime Minister Nikola Pašić's proposal for achieving union with Serbia. Within days, Serbia repudiated the short-lived Geneva Declaration. Following the Armistice of Villa Giusti between the Entente Powers and Austria-Hungary, the Kingdom of Italy sent its army to secure the part of the territory claimed by the State of Slovenes, Croats and Serbs that had been promised to Italy in the 1915 Treaty of London. Italian forces followed retreating Austro-Hungarian troops returning home from the Italian Front. The Austro-Hungarian troops normally based in Hungary were returning in trains that travelled through Međimurje, a part of the Hungary's Zala County that was located between the Drava and Mura rivers, and was largely inhabited by Croats. According to 1910 census, 82,829 out of 90,387 residents of the region were Croats. During the war, Međimurje-born Croatian lawyer and politician published a pamphlet advocating self-determination of Međumurje Croats and advocated adding the region to a common South-Slavic state referring to the Fourteen Points of the US President Woodrow Wilson. At the same time, Novak primarily accused Hungary of imposing absolutist legislation with the aim of ruling over non-Hungarians. Although banned by the Hungarian government, Novak's writing shaped the attitudes of Međimurje's Croats to Hungarian rule. In the final phase of the war, food shortages and diseases—especially Spanish flu—contributed to greater social discontent. Furthermore, security throughout Hungary and Croatia-Slavonia was poor because of Green Cadres – deserters who were surviving through banditry.
First incursion Prelude
In early November 1918, a revolt began in several villages in eastern Međimurje and quickly spread across the region. The revolt resembled class struggle but the insurrectionists also targeted anyone they perceived as enemies on ethnic grounds. They sought secession and to drive Hungarians out of the region on "Wilsonian grounds", referring to the US president's support for self-determination. The properties of prominent Hungarians were looted, including the Festetics family estate in Gornji Hrašćan and Feštetić Castle in Pribislavec. By 4 November the revolt had largely lost momentum; the next day, the Zala County prefect authorised summary court-martial proceedings in Međimurje. More than 100 people were summarily executed after perfunctory trials. Some civilians fled south across the Drava into Croatia-Slavonia; most went to the city of Varaždin but others fled to Koprivnica. By 10 November, Hungarian regular troops had restored control in a vast majority of the region and two days later they gained control of the village of Nedelišće, the last rebel stronghold.
On 10 November, a popular assembly was held in Varaždin to discuss the civil disturbances in Međimurje. National Council members blamed purported mercenaries and Hungarian Green Cadres for the violence. National Council committees based in Varaždin and Koprivnica dispatched delegations to Zagreb to seek help from the central government and from Colonel Dušan Simović, who had just arrived in Zagreb as a representative of the Royal Serbian Army. In response, National Council defence commissioner Mate Drinković dispatched Major Ivan Tomašević and Lieutenant Viktor Debeljak to Varaždin to devise a plan for the occupation of Međimurje. Tomašević found forces in Varaždin under command of Captain Stjepan Sertić, the commanding officer of the 3rd battalion of the 25th Infantry Regiment of the Royal Croatian Home Guard. A battalion that largely consisted of refugees from Međimurje was raised, as was a National Guards volunteer detachment that included high-school pupils from Varaždin, nominally reporting to the National Council. The entire force consisted of approximately 300 troops. Some of their weapons were taken from Varaždin barracks and others were from disarming soldiers of the 14th Infantry Regiment of the Royal Hungarian Honvéd and the 33rd Infantry Regiment of the Common Army, who were crossing Drava in Varaždin on their way home following the armistice. Tomašević assumed overall command, Oberleutnant Franjo Glogovec led the Međumurje battalion, and Major Marko Georgijević led the volunteer troops.
The same day, the National Council sent , Valerijan Pribićević, and Major Dragutin Perko to Belgrade, where they met with the commander of the Serbian First Army Vojvoda Petar Bojović and Prince Regent Alexander, and sought military intervention by Serbia against Hungary in Međimurje. The Regent directed Perko to meet Vojvoda Petar Mišić the next day to discuss the matter. Mišić told Perko that Serbia could not intervene due to the armistice but promised support if forces of the State of Slovenes, Croats and Serbs captured Međimurje.
Repelled advance
On 13 November, another public assembly was held in Varaždin, at which Tomašević and mayor Pero Magdić announced their plan to launch an attack across the Drava River into Međimurje at 10 p.m. that evening. Magdić pushed for a quick action, hoping to improve his political standing and had a poster calling for volunteers printed. Crowds escorted the available troops to the Drava River bridge. Once across, the attackers positioned several artillery pieces and split into three columns. Sertić led the main advance towards Čakovec, the largest town in Međimurje about to the north. The advance proceeded along the main road through the village of Pušćine. To his right, the volunteer force took the road to Čakovec through the village of Kuršanec. On the left flank, Glogovec led his troops through the village of Gornji Hrašćan before turning east towards Čakovec. According to Tomašević, the aim of the operation's first stage was to capture Čakovec and establish a bridgehead across the Drava before attempting any further advance. The advancing forces reached Čakovec in the morning of 14 November without encountering resistance. This matched the information available to the National Council, which indicated Hungarian troops had withdrawn from Međimurje, except from Čakovec railway station. Forces tasked with security of the railway in Čakovec were under command of Major Károly Györy.
There are conflicting reports on the time and direction of the arrival of additional Hungarian troops at Čakovec; the majority view is that a force several times larger than the opposition arrived in four trains from Nagykanizsa shortly before the troops commanded by Tomašević reached the town. The forces first fought near Čakovec railway station, where Hungarian forces awaited the attackers in prepared positions. The forces commanded by Tomašević fled in disarray to Varaždin across Drava bridges or, after Hungarian cavalry captured both, swam across the river to safety. The fighting concluded the same day in a truce brokered by Varaždin County prefect Franjo Kulmer and Čakovec District chief justice Pál Huszár. Kulmer and Huszár met again on 15 November to arrange the restoration of Varaždin–Čakovec railway traffic and security control of traffic across Drava bridges. Because the city boundary of Varaždin extended slightly north of the Drava River, Huszár agreed no Hungarian forces would be posted at the bridges and that security would be enforced by the State of the Slovenes, Croats and Serbs. According to Simović, Tomašević's defeat was the result of a complete lack of preparation and caused considerable fear of a Hungarian attack against Varaždin. Press reports noted at least four attackers were killed.
Second incursion Preparations for another push
On 16 November, Simović sent a new request for Serbia's military intervention on behalf of the National Council. The National Council wanted to capture Međimurje and establish a Czech Corridor (an overland link with Czechoslovakia). Three days later, Serbia rejected the request because the Armistice of Belgrade (which had concluded on 13 November) established the Drava River as the boundary of territory under Hungarian control in the area of Međimurje and Varaždin. The Hungarian envoy in Zagreb Gyula Gömbös file a report on 19 November stating that further military action against Hungarian interests in Međimurje was likely and that forces needed for this were assembling near Varaždin. On 23 November, the National Council wrote to General Louis Franchet d'Espèrey asking him to occupy Međimurje. The new attempt at capturing Međimurje was planned for 6 December with the participation of a substantially greater force. Drinković appointed Colonel Slavko Kvaternik to lead the offensive. The attack was postponed following an armed conflict in Zagreb which took place a day before the scheduled operation.