After World War I ended, the victorious allied European powers occupied the Ottoman Empire with the intention of dismembering it. The Young Turk (CUP) government fled into exile. The last Ottoman sultan, Mhammad VI Vahideddin (1861-1926), was convinced that resistance to the Allies was futile, but the Young Turk Mustafa Kemal, later Kemal Ataturk (1881-1938), refused to capitulate, and the emergence of modern Turkey is a monument to his perseverance, immortalized in his name after 1934: Kemal ("the perfect") Ataturk ("Father of the Turks"). In 1919, he gained an official post in Anatolia (Asian Turkey), from which he led a national resistance movement against both the sultan's armies and Greek occupying forces. Kemal also became, in 1919, leader of the Association of the Rights of Anatolia and Rumelia at a congress at Erzurum; his group forced Constantinople (Istanbul), seat of the government, to yield in 1920 and pass a "National Pact" asserting Turkish boundaries extant on November 11, 1918, Armistice Day ending World War I. In response, the Allies occupied Constantinople, arrested deputies, and began military opposition to the Kemalists, or nationalists. Civil war erupted, and Kemal, through a provisional parliament in Ankara, declared the sultan to be under foreign control and appealed for all Muslims to fight foreign aggrandizement. A new Fundamental Law in 1921 gave sovereignty to the Turkish people and named the nation Turkey. The civil war now flared up. The Greeks were defeated at the Battle of the Sakarya River in 1921 and retreated painfully until they surrendered in September 1922, at Smyrna (Izmir). The Kemalists received international recognition in 1921 and 1922: a treaty with Russia, Italian withdrawal of troops, French abandonment of Cilicia in Turkey, the return of Constantinople and Thrace to Turkish control. In 1922, the Kemalist parliament began the abolishment of the sultanate, and the Lausanne Conference in Switzerland (November 1922-July 1923) established modern Turkey's borders, arranged the exchange of Greek and Turkish minorities, and made the straits of the Dardanelles and Bosporus international. Turkey was proclaimed a republic on October 29, 1923, with Kemal Ataturk as its first president.