Turkey (; Turkish: Türkiye), is a transcontinental country in Eurasia, mainly in Anatolia in Western Asia, with a smaller portion on the Balkan peninsula in Southeast Europe. Turkey is a democratic, secular, unitary, parliamentary republic with a diverse cultural heritage. Turkey is bordered by eight countries: Greece and Bulgaria to the northwest; Georgia to the northeast; Armenia, the Azerbaijani exclave of Nakhchivan and Iran to the east; Iraq and Syria to the south. The country is encircled by seas on three sides: the Aegean Sea is to the west, the Black Sea to the north, and the Mediterranean Sea to the south. The Bosphorus, the Sea of Marmara, and the Dardanelles, which together form the Turkish Straits, divide Thrace and Anatolia; they also separate Europe and Asia. Ankara is the capital while Istanbul is the country's largest city and main cultural and commercial centre. Approximately 70-80% of the country's citizens identify themselves as ethnic Turks. Other ethnic groups include legally recognised (Armenians, Greeks, Jews) and unrecognised (Kurds, Arabs, Circassians, Albanians, Bosniaks, Georgians, etc.) minorities. Kurds are the largest ethnic minority group, making up approximately 20% of the population. The area of Turkey has been inhabited since the Paleolithic by various ancient Anatolian civilisations, as well as Assyrians, Greeks, Thracians, Phrygians, Urartians and Armenians. 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 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, when it disintegrated into small Turkish beyliks. In the mid-14th century the Ottomans started uniting Anatolia and created an empire encompassing much of Southeast Europe, West 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 in the 16th century, especially during the reign (1520–1566) of Suleiman the Magnificent. It remained powerful and influential for two more centuries, until important setbacks in the 17th and 18th century forced it to cede strategic territories in Europe, signalling the loss of its former military strength and wealth. After the 1913 Ottoman coup d'état which effectively put the country under the control of the Three Pashas, the Ottoman Empire decided to join the Central Powers during World War I which were ultimately defeated by the Allied Powers. During the war, the Ottoman government committed genocides against its Armenian, Assyrian and Pontic Greek citizens. Following the war, the conglomeration of territories and peoples that formerly comprised the Ottoman Empire was partitioned into several new states. The Turkish War of Independence (1919–1922), initiated by Mustafa Kemal Atatürk and his colleagues against the occupying Allies, resulted in the abolition of monarchy in 1922 and the establishment of the Republic of Turkey in 1923, with Atatürk as its first president. Atatürk enacted numerous reforms, many of which incorporated various aspects of Western thought, philosophy, and customs into the new form of Turkish government. Turkey is a charter member of the UN, an early member of NATO, and a founding member of the OECD, OSCE, OIC and 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 accession negotiations with the European Union in 2005. Turkey's growing economy and diplomatic initiatives have led to its recognition as a regional power while its location has given it geopolitical and strategic importance throughout history. Turkey's current administration headed by president Tayyip Erdoğan has reversed many of the country's earlier reforms which had been in place since the founding of the modern republic of Turkey, such as Freedom of the Press, a Legislative System of Checks and Balances, and a set of standards for secularism in government, as first enacted by Atatürk.