World War 1 began on July 28, 1914 and lasted until November 11, 1918. It started as a local European conflict between Austria-Hungary and Serbia but grew to become a global war involving 30 countries and more than 70 million military personnel. The two opposing alliances were the Allies including the UK, France, Russia, and later the US, and the Central Powers including Germany, Austria-Hungary and the Ottoman Empire. After over four years of heavy casualties on both sides from trench warfare and new military technologies, Germany agreed to an armistice, ending the war. In total over 16 million people died making it one of the deadliest conflicts in history.