Kingdom of Hungary (1920–1946) in the context of "Axis powers"

The Tripartite Pact, also known as the Berlin Pact, was an agreement between Germany, Italy, and Japan signed in Berlin on 27 September 1940 by, respectively, Joachim von Ribbentrop, Galeazzo Ciano, and Saburō Kurusu (in that order) and in the presence of Adolf Hitler. It was a defensive military alliance that was eventually joined by Hungary (20 November 1940), Romania (23 November 1940), Slovakia (24 November 1940), Bulgaria (1 March 1941), and Yugoslavia (25 March 1941). Yugoslavia's accession provoked a coup d'état in Belgrade two days later. Germany, Italy, and Hungary responded by invading Yugoslavia. The resulting Italo-German client state, known as the Independent State of Croatia, joined the pact on 15 June 1941.

The Tripartite Pact was, together with the Anti-Comintern Pact and the Pact of Steel, one of a number of agreements between Germany, Japan, Italy, and other countries of the Axis powers governing their relationship.

Banat, Bačka, and Baranya (Serbo-Croatian: Banat, Bačka i Baranja / Банат, Бачка и Барања) was a province of the Kingdom of Serbia and the Kingdom of Serbs, Croats, and Slovenes between November 1918 and 1922. It included the geographical regions of Banat, Bačka, and Baranya and its administrative center was Novi Sad. They were later separated from the country to become SAP Vojvodina in 1945 with the creation of Federal Yugoslavia; smaller parts of Baranya were incorporated into Croatia or ceded to Kingdom of Hungary, while a portion of Banat was ceded to Kingdom of Romania.

The First Czechoslovak Republic, often colloquially referred to as the First Republic, was the first Czechoslovak state that existed from 1918 to 1938, a union of ethnic Czechs and Slovaks. The country was commonly called Czechoslovakia, a compound of Czech and Slovak; which gradually became the most widely used name for its successor states. It was composed of former territories of Austria-Hungary, inheriting different systems of administration from the formerly Austrian (Bohemia, Moravia, a small part of Silesia) and Hungarian territories (mostly Upper Hungary and Carpathian Ruthenia).

After 1933, Czechoslovakia remained the only de facto functioning democracy in Central Europe, organized as a parliamentary republic. Under pressure from its Sudeten German minority, supported by neighbouring Nazi Germany, Czechoslovakia was forced to cede its Sudetenland region to Germany on 1 October 1938 as part of the Munich Agreement. It also ceded southern parts of Slovakia and Carpathian Ruthenia to Hungary and the Trans-Olza region in Silesia to Poland. This, in effect, ended the First Czechoslovak Republic. It was replaced by the Second Czechoslovak Republic, which lasted less than half a year before Germany occupied the rest of Czechoslovakia in March 1939.

Czechoslovakia (/ˌtʃɛkoʊsloʊˈvæki.ə, ˈtʃɛkə-, -slə-, -ˈvɑː-/ CHEK-oh-sloh-VAK-ee-ə, CHEK-ə-, -⁠slə-, -⁠VAH-; Czech and Slovak: Československo, Česko-Slovensko) was a landlocked country in Central Europe created in 1918 when it declared its independence from Austria-Hungary. In 1938, after the Munich Agreement, the Sudetenland became part of Nazi Germany. Between 1939 and 1945, the state ceased to exist, as Slovakia proclaimed its independence and Carpathian Ruthenia became part of Hungary, while the German Protectorate of Bohemia and Moravia was proclaimed in the remainder of the Czech Lands. In 1939, after the outbreak of World War II, former Czechoslovak president Edvard Beneš formed a government-in-exile and sought recognition from the Allies.

After World War II, Czechoslovakia was re-established under its pre-1938 borders, with the exception of Carpathian Ruthenia, which became part of the Ukrainian SSR (a republic of the Soviet Union). The Communist Party seized power in a coup in 1948. From 1948 to 1989, Czechoslovakia was part of the Eastern Bloc with a planned economy. Its economic status was formalized in membership of Comecon from 1949 and its defense status in the Warsaw Pact of 1955. A period of political liberalization in 1968, the Prague Spring, ended when the Soviet Union, assisted by other Warsaw Pact countries, invaded Czechoslovakia. In 1989, as Marxist–Leninist governments and communism were ending all over Central and Eastern Europe, Czechoslovaks peacefully deposed their communist government during the Velvet Revolution, which began on 17 November 1989 and ended 11 days later on 28 November when all of the top Communist leaders and Communist party itself resigned. On 31 December 1992, Czechoslovakia split peacefully into the two sovereign states of the Czech Republic and Slovakia.

The Second Polish Republic, officially known at the time as the Republic of Poland, was a country in Central and Eastern Europe that existed between 7 October 1918 and 6 October 1939 after being established in the final stage of World War I. The Second Republic was taken over in 1939, after it was invaded by Nazi Germany, the Soviet Union, and the Slovak Republic, marking the beginning of the European theatre of the Second World War. The Polish government-in-exile was established in Paris and later London after the fall of France in 1940.

When, after several regional conflicts, most importantly the victorious Polish-Soviet war, the borders of the state were finalized in 1922, Poland's neighbours were Czechoslovakia, Germany, the Free City of Danzig, Lithuania, Latvia, Romania, and the Soviet Union. It had access to the Baltic Sea via a short strip of coastline known as the Polish Corridor on either side of the city of Gdynia. Between March and August 1939, Poland also shared a border with the then-Hungarian governorate of Subcarpathia. In 1938, the Second Republic was the sixth largest country in Europe. According to the 1921 census, the number of inhabitants was 25.7 million. By 1939, just before the outbreak of World War II, this had grown to an estimated 35.1 million. Almost a third of the population came from minority groups: 13.9% Ukrainians; 10% Ashkenazi Jews; 3.1% Belarusians; 2.3% Germans and 3.4% Czechs and Lithuanians. At the same time, a significant number of ethnic Poles lived outside the country's borders.

The Treaty of Saint-Germain-en-Laye (French: Traité de Saint-Germain-en-Laye) was signed on 10 September 1919 by the victorious Allies of World War I on the one hand and by the Republic of German-Austria on the other. Like the Treaty of Trianon with Hungary and the Treaty of Versailles with the Weimar Republic, it contained the Covenant of the League of Nations and as a result was not ratified by the United States but was followed by the US–Austrian Peace Treaty of 1921.

The treaty signing ceremony took place at the Château de Saint-Germain-en-Laye.

The military occupation of Czechoslovakia by Nazi Germany began with the German annexation of the Sudetenland in 1938, continued with the creation of the Protectorate of Bohemia and Moravia, and by the end of 1944 extended to all parts of Czechoslovakia.

Following the Anschluss of Austria in March 1938 and the Munich Agreement in September of that same year, Adolf Hitler annexed the Sudetenland from Czechoslovakia on 1 October, giving Germany control of the extensive Czechoslovak border fortifications in this area. The incorporation of the Sudetenland into Germany left the rest of Czechoslovakia ("Rest-Tschechei" ) with a largely indefensible northwestern border. Also a Polish-majority borderland region of Trans-Olza which was annexed by Czechoslovakia in 1919, was occupied and annexed by Poland following the two-decade long territorial dispute. Finally the First Vienna Award gave to Hungary the southern territories of Slovakia and Carpathian Ruthenia, mostly inhabited by Hungarians.

The Romanian Bridgehead (Polish: Przedmoście rumuńskie; Romanian: Capul de pod român) was an area in southeastern Second Polish Republic that is now located in Ukraine. During the invasion of Poland in 1939 at the start of the Second World War, the Polish commander-in-chief, Marshal of Poland Edward Rydz-Śmigły, ordered all Polish troops fighting east of the Vistula (approximately 20 divisions still retaining the ability to co-operate) to withdraw towards Lwów and then to the hills along the borders with the Kingdom of Romania and the Soviet Union on 14 September. After the Soviets attacked on 17 September, Rydz-Śmigły ordered all units to withdraw to Romania and the Kingdom of Hungary, but communications had become disrupted although smaller units crossed outside the major battles.

The plan was a default plan in case it was impossible to defend the Polish borders, and it assumed that the Polish forces would be able to retreat to the area, organise a successful defence until the winter and hold out until the promised French offensive on the Western Front had started. Rydz-Śmigły predicted that the hills, valleys, swamps and the rivers Stryj and Dniester would provide natural lines of defence against the Nazi German advance. The area was also home to many ammunition dumps that were prepared for the third wave of Polish troops, and it was linked by transport to the Romanian port of Constanța, which could be used to resupply the Polish troops.