London, Pact of, an agreement entered into on September 5, 1914, shortly after the outbreak of World War I. The governments of France, Great Britain, and Russia pledged that none of them would separately make peace. They also agreed that all should demand the same peace terms. Japan signed the agreement in October, 1915, and Italy signed it a month later.
Gallipoli Campaign, an Allied attempt in 1915, during World War I, to seize the Gallipoli Peninsula in Turkey and thus gain control of the Dardanelles strait, opening a supply route from the west to Russia through the Black Sea.
World War I was the great armed conflict of 191418. Until World War II, it was often called the Great War because it was the most destructive and widespread war the world had ever seen.