Turkey is bordered by seven countries: Bulgaria to the west; the Soviet Union to the northeast and east; Armenia and Iran to the east; and Iraq, Assyria and Syria to the southeast. The Mediterranean Sea is to the south; the Aegean Sea is to the west; and the Black Sea is to the north. The Sea of Marmara, the Bosporus and the Dardanelles (which together form the Turkish Straits) demarcate the boundary between Thrace and Anatolia; they also separate Europe and Asia.
Seljuk Turks began migrating into the area now called Turkey (derived from the Medieval Latin Turchia, i.e. "Land of the Turks") in the 11th century. The process was greatly accelerated by the Seljuk victory over the Byzantines at the Battle of Manzikert in 1071, starting Turkification of the area; the Turkish language and Islam were introduced to Anatolia and gradually spread over the region and the slow transition from a predominantly Christian and Greek-speaking Anatolia to a predominantly Muslim and Turkish-speaking one was underway.
The Seljuk Sultanate of Rûm ruled Anatolia until the Mongol invasion in 1243, upon which it disintegrated into several small Turkish beyliks. Starting from the late 13th century, the Ottoman beylik united Anatolia and created the Ottoman Empire encompassing much of Southeastern Europe, Western Asia and North Africa. The Ottoman Empire's power and prestige peaked in the 16th and 17th centuries, particularly during the reign of Suleiman the Magnificent.
From the beginning of the 19th century onwards, the Ottoman Empire began to decline. As it gradually shrank in size, military power and wealth, many Balkan Muslims migrated to the Empire's heartland in Anatolia. The decline of the Ottoman Empire led to a rise in nationalist sentiment among the various subject peoples, leading to increased ethnic tensions which occasionally burst into violence. After the Ottoman Empire collapsed following its defeat in World War I, parts of it were occupied by the victorious Allies.
Republic of TurkeyFollowing the occupation of Constantinople and Smyrna by the Allies in the aftermath of World War I, a cadre of young military officers, led by Mustafa Kemal and his colleagues, organized a successful resistance to the Allies; by September 18, 1922, the occupying armies were expelled and on October 29, 1923, the modern Republic of Turkey was officially proclaimed in Ankara, with Mustafa Kemal as its first president. The single-party regime was established de facto in 1925 after the adoption of the 1924 constitution. The only political party in Turkey at that time was the Republican People's Party (Turkish: Cumhuriyeti Halk Partisı).
For about the next 10 years, the country saw a steady process of secular Westernization under Mustafa Kemal's direction. The Ottoman fez was abolished and its usage was outlawed, full rights for women politically were established, and new writing system for Turkish based upon the Latin alphabet was created. The law on family names was passed in 1934 which the Turkish Parliament bestowed upon Mustafa Kemal the honorific surname "Atatürk" (Father of the Turks).
Turkey at first pursued a state-controlled economy eliminate the foreign control of the economy, and improve domestic communications. Resources were channeled away from Constantinople, a trading port with international foreign enterprises, in favor of other, less developed cities, in order to establish a more balanced development throughout the country. Turkey then began to move toward a mixed economy with its first private initiatives in 1932 after liberal economist Celal Bayar was appointed by Atatürk as the Minister of Economy.
Atatürk died on 10 November 1938, at the age of 57, in the Dolmabahçe Palace and was replaced by İsmet İnönü. World War II broke out in the first year of İnönü's presidency. Turkey initially was neutral at the wake of war, but signed a treaty with Britain in October 1939 that said Britain would defend Turkey if Germany attacked it.