The Bolsheviks, originally alsoBolshevists (Russian: большевики, большевик (singular); IPA: [bəlʲʂɨˈvʲik]; derived from bol'shinstvo, "majority") were a faction of the Marxist Russian Social Democratic Labour Party (RSDLP) which split apart from the Menshevik faction at the Second Party Congress in 1903.

The Bolsheviks were the majority faction in a crucial vote, hence their name. They ultimately became the Communist Party of the Soviet Union. The Bolsheviks came to power in Russia during the October Revolution phase of the Russian Revolution of 1917, and founded the Russian Soviet Federative Socialist Republic which would later in 1922 become the chief constituent of the Soviet Union.

The Bolsheviks, founded by Vladimir Lenin and Alexander Bogdanov, were by 1905 a mass organization consisting primarily of workers under a democratic internal hierarchy governed by the principle of democratic centralism, who considered themselves the leaders of the revolutionary working class of Russia. Their beliefs and practices were often referred to as Bolshevism. Bolshevik revolutionary leader Leon Trotsky commonly used the terms "Bolshevism" and "Bolshevist" after his exile from the Soviet Union to differentiate between what he saw as true Leninism and the state and party as they existed under Stalin's leadership.

Leon Trotsky (Russian: Лев Троцкий, pronounced [ˈlʲef ˈtrot͡skʲɪj] ( listen); 7 November [O.S. 26 October] 1879 – 21 August 1940), born Lev Davidovich Bronshtein, was a Russian Marxist revolutionary and theorist, Soviet politician, and the founder and first leader of the Red Army.

Trotsky was initially a supporter of the Menshevik Internationalists faction of the Russian Social Democratic Labour Party. He joined the Bolsheviks immediately prior to the 1917 October Revolution, and eventually became a leader within the Party. During the early days of the Soviet Union, he served first as People's Commissar for Foreign Affairs and later as the founder and commander of the Red Army as People's Commissar of Military and Naval Affairs. He was a major figure in the Bolshevik victory in the Russian Civil War (1918–20). He was also among the first members of the Politburo.

After leading a failed struggle of the Left Opposition against the policies and rise of Joseph Stalin in the 1920s and the increasing role of bureaucracy in the Soviet Union, Trotsky was successively removed from power, expelled from the Communist Party, deported from the Soviet Union and assassinated on Stalin's orders. An early advocate of Red Army intervention against European fascism, Trotsky also opposed Stalin's non-aggression pact with Adolf Hitler in the late 1930s.

Adolf Hitler (German: [ˈadɔlf ˈhɪtlɐ] ( listen); 20 April 1889 – 30 April 1945) was an Austrian-born German politician and the leader of the National Socialist German Workers Party (German: Nationalsozialistische Deutsche Arbeiterpartei (NSDAP), commonly referred to as the Nazi Party). He was chancellor of Germany from 1933 to 1945 and dictator of Nazi Germany (as Führer und Reichskanzler) from 1934 to 1945. Hitler is commonly associated with the rise of fascism in Europe, World War II, and the Holocaust.

A decorated veteran of World War I, Hitler joined the German Workers' Party, precursor of the Nazi Party, in 1919, and became leader of the NSDAP in 1921. In 1923, he attempted a coup d'état, known as the Beer Hall Putsch, in Munich. The failed coup resulted in Hitler's imprisonment, during which time he wrote his memoir, Mein Kampf (My Struggle). After his release in 1924, Hitler gained popular support by attacking the Treaty of Versailles and promoting Pan-Germanism, antisemitism, and anticommunism with charismatic oratory and Nazi propaganda. After his appointment as chancellor in 1933, he transformed the Weimar Republic into the Third Reich, a single-party dictatorship based on the totalitarian and autocratic ideology of Nazism. His aim was to establish a New Order of absolute Nazi German hegemony in continental Europe.

Dietrich Eckart (23 March 1868 – 26 December 1923) was a German journalist and politician and, with Adolf Hitler, was one of the early key members of the Nazi Party (NSDAP) and a participant in the 1923 Beer Hall Putsch.

Eckart was born Johann Dietrich Eckart in 1868 in Neumarkt, Upper Palatinate (about twenty miles southeast of Nuremberg) in the Kingdom of Bavaria, the son of royal notary and lawyer Christian Eckart and his wife Anna, a devout Catholic. His mother died when he was ten years old. Young Dietrich was expelled from several schools; in 1895, his father died also, leaving him a considerable amount of money that Eckart soon spent.

Eckart initially studied law at Erlangen, later medicine at the Ludwig Maximilian University of Munich, and was an eager fencing and drinking corps member, but he finally decided in 1891 to work as a poet, playwright and journalist. Diagnosed with morphine addiction and nearly stranded, he moved to Berlin in 1899, where he wrote a number of plays, often autobiographical, becoming the protégé of Count Georg von Hülsen-Haeseler (1858 – 1922), the artistic director of the Prussian Royal Theatre. Eckart was a successful playwright, especially for his 1912 adaptation of Henrik Ibsen's Peer Gynt, one of the best attended productions of the age with more than 600 performances in Berlin alone. It was this success that not only made Eckart a wealthy man, but gave him the social contacts needed to introduce Hitler to dozens of important German citizens of the day. These introductions proved to be pivotal in Hitler's ultimate rise to power.

Sir Winston Leonard Spencer-Churchill, KG, OM, CH, TD, PC, DL, FRS, Hon. RA (30 November 1874 – 24 January 1965) was a British Conservative politician and statesman known for his leadership of the United Kingdom during the Second World War. Widely regarded as one of the greatest wartime leaders of the century, he served as Prime Minister twice (1940–45 and 1951–55). A noted statesman and orator, Churchill was also an officer in the British Army, a historian, a writer, and an artist. He is the only British prime minister to have received the Nobel Prize in Literature, and was the first person to be made an Honorary Citizen of the United States.

Churchill was born into the aristocratic family of the Dukes of Marlborough. His father, Lord Randolph Churchill, was a charismatic politician who served as Chancellor of the Exchequer; his mother, Jenny Jerome, was an American socialite. As a young army officer, he saw action in British India, the Sudan, and the Second Boer War. He gained fame as a war correspondent and wrote books about his campaigns.