World War I: Senior British and French figures, including prime ministers H. H. Asquith and Aristide Briand, met at Calais to discuss the future of the Salonika Front.

World War I or the First World War, also known as the Great War, was a global conflict between two coalitions: the Allies and the Central Powers. Main areas of conflict included Europe and the Middle East, as well as parts of Africa and the Asia-Pacific. There were important developments in weaponry including tanks, aircraft, artillery, machine guns, and chemical weapons. One of the deadliest conflicts in history, it resulted in an estimated 30 million military casualties, plus another 8 million civilian deaths from war-related causes and genocide. The movement of large numbers of people was a major factor in the deadly Spanish flu pandemic.

Herbert Henry Asquith, 1st Earl of Oxford and Asquith, known professionally as H. H. Asquith, was a British statesman and Liberal politician who was Prime Minister of the United Kingdom from 1908 to 1916. He was the last prime minister from the Liberal Party to command a majority government, and the most recent Liberal to have served as Leader of the Opposition. He played a major role in the design and passage of major liberal legislation and a reduction of the power of the House of Lords. In August 1914 Asquith took the United Kingdom of Great Britain and Ireland and the British Empire into the First World War. During 1915 his government was vigorously attacked for a shortage of munitions and the failure of the Gallipoli Campaign. He formed a coalition government with other parties, but failed to satisfy critics, was forced to resign in December 1916 and never regained power.

Aristide Pierre Henri Briand was a French statesman who served eleven terms as Prime Minister of France during the French Third Republic. He is mainly remembered for his focus on international issues and reconciliation politics during the interwar period (1918–1939).