The Oghuz languages, a major branch of the Turkic language family, are spoken by more than 150 million people in an area spanning from the Balkans to China.
The term Oghuz is applied to the Southwestern Branch of Turkic languages such as Turkish, Azerbaijani and Turkmen which are mainly spoken in Turkey, Azerbaijan, Turkmenistan, Iranian Azerbaijan, Turkmeneli, and Syria. In the 8th century, the Oghuz tribes migrated to Central Asia from the Altai Mountains, and then they started to spread out through Central Asia and Khwarezm to the Middle East and Balkans. With time, the name "Oghuz" was replaced by the names "Turkmen", "Seljuk", "Azerbaijani", and later "Ottoman Turk".
The Oghuz languages may be broken down into three main groups, based on geography and shared features:
The Ghuzz or Turkmens also known as Oguzes (a linguistic term designating the Western Turkic or Oghuz languages from the Oghur sub-division of Turkic language family) were a historical Turkic tribal confederation conventionally named the Oghuz Yabgu State in Central Asia during the early medieval period. The name Oguz is a Common Turkic word for "tribe". The Oguz confederation migrated westward from the Jeti-su area after a conflict with the Karluk branch of Uigurs. The founders of the Ottoman Empire were descendants of the Oguz Yabgu State. Today the residents of Turkey, Turkmenistan, Azerbaijan, Khorezm, Turkmens of Afghanistan, Gagauzia and Iranian Azerbaijan are descendants of Oghuz Turks and their language belongs to the Oghuz (a.k.a. southwestern Turkic) group of the Turkic languages family. According to Khazar sources, Oghuzes are the seventh son of Togarmah related to Gog and Magog.
In the 9th century, the Oguzes from the Aral steppes drove Bechens from the Emba and Ural River region toward the west. In the 10th century, they inhabited the steppe of the rivers Sari-su, Turgai, and Emba to the north of Lake Balkhash of modern-day Kazakhstan. A clan of this nation, the Seljuks, embraced Islam and in the 11th century entered Persia, where they founded the Great Seljuk Empire. Similarly in the 11th century, a Tengriist Oghuz clan—referred to as Uzes or Torks in the Russian chronicles—overthrew Pecheneg supremacy in the Russian steppe. Harried by another Turkic horde, the Kipchaks, these Oghuz penetrated as far as the lower Danube, crossed it and invaded the Balkans, where they were either crushed or struck down by an outbreak of plague, causing the survivors either to flee or to join the Byzantine imperial forces as mercenaries (1065).