World War II: In Yugoslavia, resistance leader Marshal Josip Broz Tito proclaims a provisional democratic Yugoslav government in-exile.

Josip Broz (Serbo-Croatian Cyrillic: , pronounced [jsip brz]; 7 May 1892 4 May 1980), commonly known as Tito (; Serbo-Croatian Cyrillic: , pronounced [tto]), was a Yugoslav communist revolutionary and statesman, serving in various positions from 1943 until his death in 1980. During World War II, he was the leader of the Yugoslav Partisans, often regarded as the most effective resistance movement in German-occupied Europe. He also served as the president of the Socialist Federal Republic of Yugoslavia from 14 January 1953 until his death on 4 May 1980.

He was born to a Croat father and Slovene mother in the village of Kumrovec, Austria-Hungary (now in Croatia). Drafted into military service, he distinguished himself, becoming the youngest sergeant major in the Austro-Hungarian Army of that time. After being seriously wounded and captured by the Russians during World War I, he was sent to a work camp in the Ural Mountains. He participated in some events of the Russian Revolution in 1917 and the subsequent Civil War. Upon his return to the Balkans in 1918, he entered the newly established Kingdom of Yugoslavia, where he joined the Communist Party of Yugoslavia (KPJ). He later was elected as general secretary, later president, of the League of Communists of Yugoslavia (19391980). During World War II, after the Nazi invasion of the area, he led the Yugoslav guerrilla movement, the Partisans (19411945). By the end of the war, the Partisans with the backing of the invading Soviet Union took power over Yugoslavia.

After the war, Tito was the chief architect of the Socialist Federal Republic of Yugoslavia (SFRY), serving as both prime minister (19441963), president (later President for life) (19531980), and marshal of Yugoslavia, the highest rank of the Yugoslav People's Army (JNA). Despite being one of the founders of Cominform, he became the first Cominform member to defy Soviet hegemony in 1948. He was the only leader in Joseph Stalin's time to leave Cominform and begin with his country's own socialist program, which contained elements of market socialism. Economists active in the former Yugoslavia, including Czech-born Jaroslav Vanek and Yugoslav-born Branko Horvat, promoted a model of market socialism that was dubbed the Illyrian model. Firms were socially owned by their employees and structured on workers' self-management; they competed in open and free markets. Tito managed to keep ethnic tensions under control by delegating as much power as possible to each republic. The 1974 Yugoslav Constitution defined SFR Yugoslavia as a "federal republic of equal nations and nationalities, freely united on the principle of brotherhood and unity in achieving specific and common interest." Each republic was also given the right to self-determination and secession if done through legal channels. Lastly, Tito gave Kosovo and Vojvodina, the two constituent provinces of Serbia, substantially increased autonomy, including de facto veto power in the Serbian parliament. Tito built a very powerful cult of personality around himself, which was maintained by the League of Communists of Yugoslavia after his death. Twelve years after his death, as communism collapsed in Eastern Europe, Yugoslavia dissolved and descended into a series of interethnic wars.

Some historians criticize Tito's presidency as authoritarian, while others see him as a benevolent dictator. He was a popular public figure both in Yugoslavia and abroad. Viewed as a unifying symbol, his internal policies maintained the peaceful coexistence of the nations of the Yugoslav federation. He gained further international attention as the chief leader of the Non-Aligned Movement, alongside Jawaharlal Nehru of India, Gamal Abdel Nasser of Egypt, Kwame Nkrumah of Ghana, and Sukarno of Indonesia. With a highly favourable reputation abroad in both Cold War blocs, he received some 98 foreign decorations, including the Legion of Honour and the Order of the Bath.

The Kingdom of Yugoslavia (Serbo-Croatian: Kraljevina Jugoslavija / Краљевина Југославија; Slovene: Kraljevina Jugoslavija) was a state in Southeast and Central Europe that existed from 1918 until 1941. From 1918 to 1929, it was officially called the Kingdom of Serbs, Croats and Slovenes (Serbo-Croatian: Kraljevina Srba, Hrvata i Slovenaca / Краљевина Срба, Хрвата и Словенаца; Slovene: Kraljevina Srbov, Hrvatov in Slovencev), but the term "Yugoslavia" (literally "Land of South Slavs") was its colloquial name due to its origins. The official name of the state was changed to "Kingdom of Yugoslavia" by King Alexander I on 3 October 1929.The preliminary kingdom was formed in 1918 by the merger of the provisional State of Slovenes, Croats and Serbs (itself formed from territories of the former Austria-Hungary, encompassing today's Bosnia and Herzegovina and most of today's Croatia and Slovenia) and Banat, Bačka and Baranja (that had been part of the Kingdom of Hungary within Austria-Hungary) with the formerly independent Kingdom of Serbia. In the same year, the Kingdom of Montenegro also proclaimed its unification with Serbia, whereas the regions of Kosovo and Vardar Macedonia had become parts of Serbia prior to the unification.The state was ruled by the Serbian dynasty of Karađorđević, which previously ruled the Kingdom of Serbia under Peter I from 1903 (after the May Coup) onward. Peter I became the first king of Yugoslavia until his death in 1921. He was succeeded by his son Alexander I, who had been regent for his father. He was known as "Alexander the Unifier" and he renamed the kingdom "Yugoslavia" in 1929. He was assassinated in Marseille by Vlado Chernozemski, a member of the Internal Macedonian Revolutionary Organization (IMRO), during his visit to France in 1934. The crown passed to his 11-year-old son Peter. Alexander's cousin Paul ruled as Prince regent until 1941, when Peter II came of age. The royal family flew to London the same year, prior to the country being invaded by the Axis powers.

In April 1941, the country was occupied and partitioned by the Axis powers. A royal government-in-exile, recognized by the United Kingdom and, later, by all the Allies, was established in London. In 1944, after pressure from the British Prime Minister Winston Churchill, the King recognized the government of Democratic Federal Yugoslavia as the legitimate government. This was established on 2 November following the signing of the Treaty of Vis by Ivan Šubašić (on behalf of the Kingdom) and Josip Broz Tito (on behalf of the Yugoslav Partisans).