Józef Piłsudski in the context of "Polish-Soviet War"

The Polish Socialist Party (Polish: Polska Partia Socjalistyczna, PPS) is a democratic socialist political party in Poland.

It was one of the most significant parties in Poland from its founding in 1892 until its forced merger with the communist Polish Workers' Party to form the Polish United Workers' Party in 1948. Józef Piłsudski, founder of the Second Polish Republic, was a member of and later led the PPS in the early 20th century.

Symon Vasyliovych Petliura (Ukrainian: Симон Васильович Петлюра; 22 May [O.S. 10 May] 1879 – 25 May 1926) was a Ukrainian politician and journalist. He was the Supreme Commander of the Ukrainian People's Army (UNA) and led the Ukrainian People's Republic during the Ukrainian War of Independence, a part of the wider Russian Civil War.

Petliura was born to a family of Cossack heritage in Poltava. From an early age he embraced socialism and Ukrainian nationalism, which he advocated through his highly prolific career as a journalist. After the 1917 February Revolution overthrew the Tsarist monarchy, the Ukrainian People's Republic was proclaimed and Petliura was elected head of its military. The Republic was briefly interrupted by the pro-German Ukrainian State, but in late 1918 Petliura, along with other members of the socialist Directorate of Ukraine, organised a revolt and overthrew the regime, restoring the Republic. He became the leader of the Directorate in early 1919, after the Bolsheviks invaded Ukraine and captured its capital. Facing imminent defeat, Petliura entered an alliance with Józef Piłsudski's Poland. The Polish–Soviet War concluded with Poland remaining independent and gaining some Ukrainian and Belorussian lands, while most of Ukraine remained under Soviet control, forcing Petliura into exile. He initially directed the government-in-exile from Poland, but eventually settled in Paris.

The Treaty of Warsaw (also the Polish–Ukrainian or Petliura–Piłsudski Alliance or Agreement) of April 1920 was a military-economical alliance between the Second Polish Republic, represented by Józef Piłsudski, and the Ukrainian People's Republic, represented by Symon Petliura, against Bolshevik Russia. The treaty was signed on 21 April 1920, with a military addendum on 24 April.

The alliance was signed during the Polish-Soviet War, just before the Polish Kiev offensive. Piłsudski was looking for allies against the Bolsheviks and hoped to create a Międzymorze alliance; Petliura saw the alliance as the last chance to create an independent Ukraine.

The 1920s (pronounced "nineteen-twenties" often shortened to the "'20s" or the "Twenties") was a decade that began on January 1, 1920, and ended on December 31, 1929. Primarily known for the economic boom that occurred in the Western World following the end of World War I (1914–1918), the decade is frequently referred to as the "Roaring Twenties" or the "Jazz Age" in America and Western Europe, and the "Golden Twenties" in Germany, while French speakers refer to the period as the "Années folles" ('crazy years') to emphasize the decade's social, artistic, and cultural dynamism.

The devastating Wall Street crash in October 1929 is generally viewed as a harbinger of the end of 1920s prosperity in North America and Europe. In the Soviet Union, the New Economic Policy was created by the Bolsheviks in 1921, to be replaced by the first five-year plan in 1928. The 1920s saw the rise of radical political movements, with the Red Army triumphing against White movement forces in the Russian Civil War, and the emergence of far-right political movements in Europe. In 1922, the fascist leader Benito Mussolini seized power in Italy. Other dictators that emerged included Józef Piłsudski in Poland, and Peter and Alexander Karađorđević in Yugoslavia. First-wave feminism made advances, with women gaining the right to vote in the United States (1920), Albania (1920), Ireland (1921), and with suffrage being expanded in Britain to all women over 21 years old (1928).

54°30′N 25°45′E / 54.500°N 25.750°E / 54.500; 25.750The Republic of Central Lithuania (Polish: Republika Litwy Środkowej, Lithuanian: Vidurio Lietuvos Respublika), commonly known as the Central Lithuania, and the Middle Lithuania (Polish: Litwa Środkowa, Lithuanian: Vidurinė Lietuva, Belarusian: Сярэдняя Літва, romanized: Siaredniaja Litva), was an unrecognized short-lived puppet state of Poland, that existed from 1920 to 1922. It was founded on 12 October 1920, after the successful Żeligowski Mutiny, during which the volunteer 1st Lithuanian–Belarusian Division under the command of general Lucjan Żeligowski seized the Vilnius Region that Lithuania made claims to. It was incorporated into Poland on 18 April 1922.

Vilnius, the historical capital of Lithuania, had a majority Polish-speaking population with a Lithuanian-speaking minority of only 2–3%. Therefore, the Polish authorities decided that the region should belong to the newly-established Polish state, and attempted to implement this idea using military force, ignoring the Curzon Line and taking advantage of the fact that victorious Poles after the Battle of Warsaw were advancing to the East against the Bolsheviks in the Polish–Soviet War. The Poles reasoned that they were justified in seizing as many mixed areas as possible, as well as to protect the Catholic, predominantly Polish-speaking population in disputed areas. Being utterly militarily outmatched, Lithuania did not stand a chance to maintain control of the region. This led to the renewal of Polish–Lithuanian War, where the so-called Żeligowski Mutiny, secretly ordered by Józef Piłsudski, was part of the military operation, fully supported and backed on the flanks by the Polish army, and consequently to the establishment of the so-called Republic of Central Lithuania.

Stanisław Wojciechowski (Polish: [staˈɲiswaf vɔjt͡ɕɛˈxɔfskʲi]; 15 March 1869 – 9 April 1953) was a Polish politician and scholar who served as President of Poland between 1922 and 1926, during the Second Polish Republic.

He was elected president in 1922, following the assassination of his predecessor Gabriel Narutowicz. During his presidency, Wojciechowski and his erstwhile friend Józef Piłsudski disagreed on the political direction of the nation. In 1926, Piłsudski staged a military coup, which resulted in Wojciechowski resigning from office.