Mustafa İsmet İnönü (24 September 1884 – 25 December 1973) was a Turkish politician and military officer who served as the president of Turkey from 1938 to 1950, and as its prime minister three times: from 1923 to 1924, 1925 to 1937, and 1961 to 1965.
İnönü is acknowledged by many as Mustafa Kemal Atatürk's right-hand man, with their friendship going back to the Caucasus campaign. In the Greco-Turkish War of 1919–1922, he served as the first chief of the General Staff from 1922 to 1924 for the regular Turkish army, during which he commanded forces during the First and Second Battles of İnönü. Atatürk bestowed İsmet with the surname İnönü, the site of the battles, when the 1934 Surname Law was adopted. He served as the chief negotiator for the Ankara government, first as an army general following the defeat of invading forces during the Armistice of Mudanya talks, later as Minister of Foreign Affairs at the Lausanne Conferences (1922–1923). He secured recognition of the Turkish victory by the Allies and replacing the imposed Treaty of Sèvres with the Treaty of Lausanne. As his prime minister for most of his presidency, İnönü executed many of Atatürk's modernizing and nationalist reforms. Some claim that, İnönü gave the orders to carry out the Zilan massacre.
