The Turkish people (Turkish: Türk ulusu), also known as the "Turks" (Türkler) are defined mainly as citizens of the Republic of Turkey but also refers to the sizeable Turkish minorities who are still present in the former lands of the Ottoman Empire (mainly in Bulgaria, Cyprus, Georgia, Greece, Iraq, Kosovo, Macedonia, Romania and Syria) as well as the large Turkish immigrant communities which have been established in Europe (particularly in Germany, France, the United Kingdom, and the Netherlands), as well as in North America and Australia. The name Turk (Chinese: ??, pinyin: tu jué; jyutping: duk kyut) was first applied to a clan of tribal chieftains (known as Ashina) who overthrew the ruling Rouran confederency, and founded the nomadic Göktürk Empire ("Celestial Turks") These nomads roamed in the Altai Mountains (and thus are known as Altaic peoples) in northern Mongolia and on the steppes of Central Asia. The Göktürks were ruled by Khans whose influences extended during the sixth to eighth centuries from the Aral Sea to the Hindu Kush in the land bridge known as Transoxania. In the eighth century, some Turkic tribes, among them the Oghuz, moved south of the Oxus River, while others migrated west to the northern shore of the Black Sea. (Levitt, 21-32)
The name Türk spread as a political designation during the period of Göktürk imperial hegemony to their subject Turkic and non-Turkic peoples. Subsequently, it was adopted as a generic ethnonym designating most if not all of the Turkic-speaking tribes in Central Asia by the Muslim peoples with whom they came into contact. The imperial era also provided a legacy of political and social organisation (with deep roots in pre-Türk Inner Asia) that in its Türk form became the common inheritance of the Turkic groupings of Central Asia. (Levitt, 21-32)
The Seljuks (Turkish Selçuklular; Persian: ???????? ?aljuqiyan; Arabic ????? Saljuq, or ???????? al-Salajiqa) were a Turkish tribe from Central Asia. In 1037, they entered Persia and established their first powerful state, called by historians the Empire of the Great Seljuks. They captured Baghdad in 1055 and a relatively small contingent of warriors (around 5,000 by some estimates) moved into eastern Anatolia. In 1071, the Seljuks engaged the armies of the Byzantine Empire at Manzikert (Malazgirt), north of Lake Van. The Byzantines experienced minor casualties despite the fact that Emperor Romanus IV Diogenes was captured. With no potent Byzantine force to stop them, the Seljuks took control of most of Eastern and Central Anatolia. (Standage, 145-199)
They established their capital at Konya and ruled what would be known as the Seljuk Sultanate of Rum. The success of the Seljuk Turks stimulated a response from Latin Europe in the form of the First Crusade. A counteroffensive launched in 1097 by the Byzantines with the aid of the Crusaders dealt the Seljuks a decisive defeat. Konya fell to the Crusaders, and after a few years of campaigning, Byzantine rule was restored in the western third of Anatolia. Although a Turkish revival in the 1140s nullified much of the Christian gains, ...