World War II: The United States declares war on Bulgaria, Hungary, and Romania.
The Kingdom of Hungary was a monarchy in Central Europe that existed for nearly a millennium, from the Middle Ages into the 20th century. The Principality of Hungary emerged as a Christian kingdom upon the coronation of the first king Stephen I at Esztergom around the year 1000; his family (the rpd dynasty) led the monarchy for 300 years. By the 12th century, the kingdom became a European middle power within the Western world.Due to the Ottoman occupation of the central and southern territories of Hungary in the 16th century, the country was partitioned into three parts: the Habsburg Royal Hungary, Ottoman Hungary, and the semi-independent Principality of Transylvania. The House of Habsburg held the Hungarian throne after the Battle of Mohcs in 1526 continuously until 1918 and also played a key role in the liberation wars against the Ottoman Empire.
From 1867, territories connected to the Hungarian crown were incorporated into Austria-Hungary under the name of Lands of the Crown of Saint Stephen. The monarchy ended with the deposition of the last king Charles IV in 1918, after which Hungary became a republic. The kingdom was nominally restored during the "Regency" of 19201946, ending under the Soviet occupation in 1946.The Kingdom of Hungary was a multiethnic state from its inception until the Treaty of Trianon and it covered what is today Hungary, Slovakia, Transylvania and other parts of Romania, Carpathian Ruthenia (now part of Ukraine), Vojvodina (now part of Serbia), the territory of Burgenland (now part of Austria), Meimurje (now part of Croatia), Prekmurje (now part of Slovenia) and a few villages which are now part of Poland. From 1102 it also included the Kingdom of Croatia, being in personal union with it, united under the King of Hungary.
According to the demographers, about 80 percent of the population was made up of Hungarians before the Battle of Mohcs, however in the mid-19th century out of a population of 14 million less than 6 million were Hungarian due to the resettlement policies and continuous immigration from neighboring countries. Major territorial changes made Hungary ethnically homogeneous after World War I. Nowadays, more than nine-tenths of the population is ethnically Hungarian and speaks Hungarian as their mother tongue.
Today, the feast day of the first king Stephen I (20 August) is a national holiday in Hungary, commemorating the foundation of the state (Foundation Day).
The Tsardom of Bulgaria (Bulgarian: Царство България, romanized: Tsarstvo Balgariya), also referred to as the Third Bulgarian Tsardom (Bulgarian: Трето Българско Царство, romanized: Treto Balgarsko Tsarstvo), sometimes translated in English as Kingdom of Bulgaria (Bulgarian: Крáлство България, romanized: Kralstvo Balgariya), was a constitutional monarchy in Southeastern Europe, which was established on 5 October (O.S. 22 September) 1908, when the Bulgarian state was raised from a principality to a Tsardom.Ferdinand, founder of the royal family, was crowned a Tsar at the Declaration of Independence, mainly because of his military plans and for seeking options for unification of all lands in the Balkans region with an ethnic Bulgarian majority (lands that had been seized from Bulgaria and given to the Ottoman Empire in the Treaty of Berlin).
The state was almost constantly at war throughout its existence, lending to its nickname as "the Balkan Prussia". For several years Bulgaria mobilized an army of more than 1 million people from its population of about 5 million, and in the 1910s, it engaged in three wars – the First and Second Balkan Wars, and the First World War. Following the First World War, the Bulgarian army was disbanded and forbidden to exist by the Allied Powers, and all plans for national unification of the Bulgarian lands failed.
Less than two decades later, Bulgaria once again went to war for national unification as part of the Second World War, and once again found itself on the losing side, until it switched sides to the Allies in 1944. In 1946, the monarchy was abolished, its final Tsar was sent into exile, and the Kingdom was replaced by the People's Republic of Bulgaria.