Archduke Franz Ferdinand Carl Ludwig Joseph Maria of Austria was the heir presumptive to the throne of Austria-Hungary.

precipitated Austria-Hungary's declaration of war against Serbia

Gavrilo Princip was a Bosnian Serb student who assassinated Archduke Franz Ferdinand, heir presumptive to the throne of Austria-Hungary, and his wife Sophie, Duchess von Hohenberg, in Sarajevo on 28 June 1914.

assassinated Archduke Franz Ferdinand of Austria-Hungary,

Vladimir Ilyich Ulyanov, better known as Vladimir Lenin, was a Russian revolutionary, politician and political theorist who was the founder and first head of government of Soviet Russia from 1917 until his death in 1924, and of the Soviet Union from 1922 until his death.

Lenin briefly returned to Russia during the failed Revolution of 1905, and during the First World War campaigned for its transformation into a Europe-wide proletarian revolution, which, as a Marxist, he believed would cause the end of capitalism and the rise of socialism.

Wilhelm II was the last German Emperor and King of Prussia from 1888 until his abdication in 1918, which marked the end of the German Empire as well as the Hohenzollern dynasty's 300-year rule of Prussia.

rash assurance of unlimited support to Austria-Hungary

Nicholas II or Nikolai II was the last reigning Emperor of Russia, King of Congress Poland, and Grand Duke of Finland from 1 November 1894 until his abdication on 15 March 1917.

gave support to the economic and political reforms promoted by his prime ministers, Sergei Witte and Pyotr Stolypin.

Georges Benjamin Clemenceau was a French statesman who served as Prime Minister of France from 1906 to 1909 and again from 1917 until 1920. A physician turned journalist, he played a central role in the politics of the Third Republic, particularly amid the end of the First World War.

Prime Minister of France

George V was King of the United Kingdom and the British Dominions, and Emperor of India, from 6 May 1910 until his death in 1936. George was born during the reign of his paternal grandmother, Queen Victoria, as the second son of the Prince and Princess of Wales.

meeting Allied heads of state, inspecting troops and visiting the wounded.

Sir Winston Leonard Spencer Churchill was a British statesman, military officer, and writer who was Prime Minister of the United Kingdom from 1940 to 1945 and again from 1951 to 1955. Apart from 1922 to 1924, he was a member of Parliament from 1900 to 1964 and represented a total of five constituencies.

helped orchestrate the disastrous Dardanelles naval campaign and was also involved in the planning of the military landings on Gallipoli,

Thomas Woodrow Wilson was an American politician and academic who served as the 28th president of the United States from 1913 to 1921. A member of the Democratic Party, Wilson served as the president of Princeton University and as the governor of New Jersey before winning the 1912 presidential election.

after a policy of neutrality at the outbreak of World War I, Wilson led America into war in order to “make the world safe for democracy.” Like Roosevelt before him, Woodrow Wilson regarded himself as the personal representative of the people.

John Joseph Pershing GCB, nicknamed "Black Jack", was an American army general who served as the commander of the American Expeditionary Forces during World War I from 1917 to 1920.

successfully led American and French forces in an offensive against the German line in the Saint-Mihiel salient.

Ferdinand Foch was a French general, Marshal of France and a member of the Académie Française and Académie des Sciences. He distinguished himself as Supreme Allied Commander on the Western Front during the First World War in 1918.

He stopped the German offensive and launched a war-winning counterattack.

Field Marshal Douglas Haig, 1st Earl Haig, was a senior officer of the British Army. During the First World War he commanded the British Expeditionary Force on the Western Front from late 1915 until the end of the war.

commanded the British Army