Turkey , officially the Republic of Turkey ), is a transcontinental country located mainly on the Anatolian peninsula in Western Asia, with a smaller portion on the Balkan peninsula in Southeastern Europe. East Thrace, the part of Turkey in Europe, is separated from Anatolia by the Sea of Marmara, the Bosporus and the Dardanelles . Istanbul, which straddles Europe and Asia, is the largest city in the country, while Ankara is the capital. Turkey is bordered on its northwest by Greece and Bulgaria; north by the Black Sea; northeast by Georgia; east by Armenia, the Azerbaijani exclave of Nakhchivan and Iran; southeast by Iraq; south by Syria and the Mediterranean Sea; and west by the Aegean Sea. Approximately 70 to 80 percent of the country's citizens identify as Turkish, while Kurds are the largest minority, at between 15 to 20 percent of the population.At various points in its history, the region has been inhabited by diverse civilisations including the ancient Hattians and Hurrians, the Anatolian peoples such as the Hittites and Luwians, as well as the Assyrians, Greeks, Thracians, Phrygians, Urartians, Galatians, and Armenians. Hellenization started during the era of Alexander the Great and continued into the Byzantine era. The Seljuk Turks began migrating into the area in the 11th century, and their victory over the Byzantines at the Battle of Manzikert in 1071 symbolises the foundation of Turkey for many Turkish nationalists. The Seljuk Sultanate of Rûm ruled Anatolia until the Mongol invasion in 1243, when it disintegrated into small Turkish principalities called beyliks. Beginning in the late 13th century, the Ottomans started uniting the beyliks and conquering the Balkans. The Turkification of Anatolia increased during the Ottoman period. After Mehmed II conquered Constantinople in 1453, Ottoman expansion continued under Selim I. During the reign of Suleiman the Magnificent, the Ottoman Empire encompassed much of Southeast Europe, West Asia and North Africa and became a world power. From the late 18th century onwards, the empire's power declined with a gradual loss of territories and wars. In an effort to consolidate the weakening social and political foundations of the empire, Mahmud II started a period of modernisation in the early 19th century, bringing reforms in all areas of the state including the military and bureaucracy, along with the emancipation of all citizens.The 1913 coup d'état effectively put the country under the control of the Three Pashas, who were largely responsible for the Empire's entry into World War I in 1914. During World War I, the Ottoman government committed genocides against its Armenian, Assyrian and Pontic Greek subjects. After the Ottomans and the other Central Powers lost the war, the conglomeration of territories and peoples that had composed the Ottoman Empire was partitioned into several new states. The Turkish War of Independence, initiated by Mustafa Kemal Atatürk and his comrades against the occupying Allied Powers, resulted in the abolition of the sultanate on 1 November 1922, the replacement of the Treaty of Sèvres with the Treaty of Lausanne , and the establishment of the Republic of Turkey on 29 October 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, the IMF, and the World Bank, and a founding member of the OECD, OSCE, BSEC, OIC, and G20. After becoming one of the early members of the Council of Europe in 1950, 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. In a non-binding vote on 13 March 2019, the European Parliament called on the EU governments to suspend Turkey's accession talks; which, despite being stalled since 2018, remain active as of 2020. Turkey's economy and diplomatic initiatives have led to its recognition as a regional power and a newly industrialized state by several analysts, while its location has given it geopolitical and strategic importance throughout history. Turkey is a secular, unitary, formerly parliamentary republic that adopted a presidential system with a referendum in 2017; the new system came into effect with the presidential election in 2018. Turkey's current administration, headed by President Recep Tayyip Erdoğan of the AKP, has enacted measures to increase the influence of Islam and undermine Kemalist policies and freedom of the press.