Kingdom of Hungary (1920–46) in the context of "Balkans campaign (World War II)"

The Kingdom of Hungary, referred to retrospectively as the Regency, the Horthy era, the Horthy regime, and Horthyist Hungary, existed as a country from 1920 to 1946 under the rule of Miklós Horthy for the most of its existence, who officially represented the Hungarian monarchy after a period of revolutions and the counter-revolution as the Regent of Hungary. In reality there was no king, and attempts by King Charles IV to return to the throne shortly before his death were prevented by Horthy.

Horthy came to power after supressing the Hungarian Soviet Republic during the period of White Terror, installing an authoritarian political system relying on the traditional economic elites and bureaucracy. Hungary under Horthy was characterized by its conservative, nationalist, and fiercely anti-communist character; some historians have described this system as para-fascist. The government was based on an unstable alliance of conservatives and right-wingers; while conservatism was predominant in the 1920s, afterwards Horthy manoeuvered between conservatives and the radical right with fascist leanings. Foreign policy was characterized by revisionism — the total or partial revision of the Treaty of Trianon, which had seen Hungary lose over 70% of its historic territory along with over three million Hungarians, who mostly lived in the border territories outside the new borders of the kingdom, in the Kingdom of Romania and the newly created states of Czechoslovakia and the Kingdom of Serbs, Croats and Slovenes (in greatly enlarged Romania there also remained a significant Hungarian population in Székely Land). Republican Austria, the successor of the former other half of the dual monarchy also received some minor territory from Hungary. Thus the post-1918 kingdom can be described as a rump state. Hungary's interwar politics were dominated by a focus on the territorial losses suffered from this treaty, with the resentment continuing until the present. After a period of international isolation in the 1920s, it began maintaining ties with Fascist Italy and Nazi Germany.