The Ottoman Empire entered World War I on October 29, 1914. This followed a series of events including a secret alliance with Germany and the naval bombardment of Russian ports in the Black Sea by Ottoman warships, which was a decisive act leading to the Ottoman Empire’s full entry into the war on the side of the Central Powers.
As the Ottoman Empire entered WWI, it consisted of what is now present day Turkey, Syria, Lebanon, Israel (part of Palestine), Palestine, Jordan, Iraq, part of Saudi Arabia, Kuwait, Qatar, Bahrain, Cyprus, part of Yemen, Greece (part of Eastern Thrace and some Aegean islands), part of Bulgaria, Georgia (part of Batumi Oblast).