During the 1930s, the newly independent Kingdom of Hungary, under the regency of former Austro-Hungarian admiral Miklós Horthy, adopted an irredentist policy similar to Nazi Germany’s. Notably, Hungary used its relationship with Germany to attempt to revise the 1920 Treaty of Trianon, which had stripped the country of two-third of its territory and population.

After Hungary openly repudiated the Treaty’s restrictions on its armed forces, and with Germany well into its own revision of the Versailles Treaty, with the remilitarization of the Rhineland and the Anschluss of Austria, Adolf Hitler and Benito Mussolini sought to peacefully enforce the claims of Hungarians on territories the Kingdom had lost to Czechoslovakia and Romania in 1920.

By 1938, following the Munich Agreement, the First Vienna Award transferred the largely Magyar-populated territories in southern Slovakia and southern Carpathian Rus from Czechoslovakia to Hungary, preventing, for now, the increasingly tense situation from blowing up into a full-scale war. But the partition did not fully satisfy Hungary’s territorial ambitions and border clashes continued to take place.

Meanwhile, in neighbouring Slovakia, which had gained greater autonomy within Czechoslovakia after Munich, the authoritarian tendencies of Catholic priest Jozef Tiso became more and more evident following his party’s landslide win in the Slovak elections of December 1938. Watching with growing concerns developments in the eastern part of their union, Czechoslovak leaders in Prague dismissed Tiso and replaced him by Karel Sidor.

In early March 1939, Adolf Hitler invited Tiso to Berlin to make a pact with the recently-deposed Slovak leader. Threatening to abandon Slovakia to the will of Hungary’s territorial ambitions, and promising to protect and safeguard the integrity of the Slovak state, Hitler urged Tiso to break off from their Czech neighbours. And on March 14, the Slovak Parliament, convened at Tiso’s request, unanimously declared independence.

Claiming that the unrest in Czechoslovakia was a threat to German security, Adolf Hitler declared support for the Slovak regime and immediatly sent troops into Czechoslovakia for a forceful annexation of the Czech lands. After recognizing the new independent Slovak state, Hungary soon requested Germany to mediate further transfer of territory from Slovakia to Hungary.

But before any final agreement came to fruition and without any formal declaration of war, Hungarian troops invaded Slovakia from Carpatho-Ukraine on March 23, starting the Slovak-Hungarian War, also known as the Little War. Catching both Slovakia and Germany off guard, Hungarian troops advanced quickly into eastern Slovakia, with the instruction to “proceed as far to the west as possible”.

By March 24, the Slovak army able to regroup and organize a counterattack, soon forcing the heavily-outnumbered Hungarians to fall back from towards their main line on the Okna River. But by then the Hungarians were well-entrenched and had ample anti-tank weaponry to counter Slovak armored cars and light tanks, which represented the only slight advantage possessed by the Slovaks.

Embarrassed by the war and torn between its new obligation towards the Slovak State and its friendly relations with Hungary, Germany soon began to assert pressure for an end to the fighting, which had largely ceased by March 31. On April 4, a peace treaty was signed in Budapest, which forced Slovakia to cede to Hungary a 1,697 square-kilometer strip of eastern Slovak territory, corresponding today to the area around the towns of Stakčín and Sobrance.

In addition to the eight Hungarian and 22 Slovak soldiers killed in action, the Little War between Slovakia and Hungary caused the death of 36 Slovak citizens.