During World War II, the Kingdom of Hungary was a member of the Axis powers. In the 1930s, the Kingdom of Hungary relied on increased trade with Fascist Italy and Nazi Germany to pull itself out of the Great Depression. Hungarian politics and foreign policy had become more stridently nationalistic by 1938, and Hungary adopted an irredentist policy similar to Germany's, attempting to incorporate ethnic Hungarian areas in neighboring countries into Hungary. Hungary benefited territorially from its relationship with the Axis. Settlements were negotiated regarding territorial disputes with the Czechoslovak Republic, the Slovak Republic, and the Kingdom of Romania. On November 20, 1940, Hungary became the fourth member to join the Axis powers when it signed the Tripartite Pact. The following year, Hungarian forces participated in the invasion of Yugoslavia and the invasion of the Soviet Union. Their participation was noted by German observers for its particular cruelty, with occupied peoples subjected to arbitrary violence. Hungarian volunteers were sometimes referred to as engaging in "murder tourism."

Miklós Kállay de Nagykálló was a Hungarian politician who served as Prime Minister of Hungary during World War II, from 9 March 1942 to 22 March 1944. By early 1942, Hungarian Regent Admiral Miklós Horthy was seeking to put some distance between himself and Hitler's regime. He dismissed the pro-German prime minister, László Bárdossy, and replaced him with Kállay, a moderate whom Horthy expected to loosen Hungary's ties to Germany.