Turkey (/ˈtɜːrki/; Turkish: Türkiye[ˈtyɾcije]), officially the Republic of Turkey (Turkish: Türkiye Cumhuriyeti), is a parliamentary republic in Eurasia, largely located in Western Asia, with the smaller portion of Eastern Thrace in Southeast Europe. Turkey is bordered by eight countries: Syria and Iraq to the south; Iran, Armenia, and the Azerbaijani exclave of Nakhchivan to the east; Georgia to the northeast; Bulgaria to the northwest; and Greece to the west. The Black Sea is to the north, the Mediterranean Sea to the south, and the Aegean Sea to the west. The Bosphorus, the Sea of Marmara, and the Dardanelles (which together form the Turkish Straits) demarcate the boundary between Thrace and Anatolia; they also separate Europe and Asia. Turkey's location at the crossroads of Europe and Asia makes it a country of significant geostrategic importance.
Turkey has been inhabited since the paleolithic age, including various ancient Anatolian civilizations, Aeolian, Dorian and Ionian Greeks, Thracians, Armenians, and Assyrians. After Alexander the Great's conquest, the area was Hellenized, a process which continued under the Roman Empire and its transition into the Byzantine Empire. The Seljuk Turks began migrating into the area in the 11th century, starting the process of Turkification, which was greatly accelerated by the Seljuk victory over the Byzantines at the Battle of Manzikert in 1071. 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 Ottomans united Anatolia and created an empire encompassing much of Southeastern Europe, Western Asia and North Africa, becoming a major power in Eurasia and Africa during the early modern period. The empire reached the peak of its power between the 15th and 17th centuries, especially during the 1520–66 reign of Suleiman the Magnificent. After the second Ottoman siege of Vienna in 1683 and the end of the Great Turkish War in 1699, the Ottoman Empire entered a long period of decline. The Tanzimat reforms of the 19th century, which aimed to modernize the Ottoman state, proved to be inadequate in most fields, and failed to stop the dissolution of the empire. The Ottoman Empire entered World War I (1914–18) on the side of the Central Powers and was ultimately defeated. During the war, major atrocities were committed by the Ottoman government against its Armenian, Assyrian and Pontic Greek citizens. Following the war, the huge conglomeration of territories and peoples that formerly comprised the Ottoman Empire was divided into several new states. The Turkish War of Independence (1919–22), initiated by Mustafa Kemal Atatürk and his colleagues in Anatolia, resulted in the establishment of the modern Republic of Turkey in 1923, with Atatürk as its first president.
Turkey is a democratic, secular, unitary, constitutional republic with a diverse cultural heritage. The country's official language is Turkish, a Turkic language spoken natively by approximately 85 percent of the population. According to the World Factbook, 70–75 percent of the population are ethnic Turks, while the Kurds are the largest minority at 18%. The vast majority of the population is Sunni Muslim, with Alevis making up the largest religious minority. Turkey is a member of the UN, NATO, OECD, OSCE, OIC and the G-20. After becoming one of the first members of the Council of Europe in 1949, Turkey became an associate member of the EEC in 1963, joined the EU Customs Union in 1995 and started full membership negotiations with the European Union in 2005. Turkey's growing economy and diplomatic initiatives have led to its recognition as a regional power.