The Great Seljuq Empire (Turkish: Büyük Selçuklu Devleti, Persian: دولت سلجوقیان‎) was a medieval Persianate,Turko-PersianSunni Muslim empire, originating from the Qynyq branch of Oghuz Turks. The Seljuq Empire controlled a vast area stretching from the Hindu Kush to eastern Anatolia and from Central Asia to the Persian Gulf. From their homelands near the Aral sea, the Seljuqs advanced first into Khorasan and then into mainland Persia before eventually conquering eastern Anatolia.

The Seljuq empire was founded by Tughril Beg in 1037 after the efforts by the founder of the Seljuq dynasty, Seljuq Beg, back in the first quarter of the eleventh century. Seljuq Beg's father was in a higher position in the Oghuz Yabgu State, and gave his name both to the state and the dynasty. The Seljuqs united the fractured political scene of the Eastern Islamic world and played a key role in the first and second crusades. Highly Persianized in culture and language, the Seljuqs also played an important role in the development of the Turko-Persian tradition, even exporting Persian culture to Anatolia. The Seljuqs conquest gave impetus to the progressive Turkicization of parts of Anatolia, Iran and the Caucasus.

The Turkomen also known as Oghuz Turks (a linguistic term designating the Western Turkic or Oghuz languages from the Oghur languages) were a historical Turkic tribal confederation in Central Asia during the early medieval Turkic expansion. The name Oghuz is just the Common Turkic  word for "tribe". They are referred to as "Western Turks" because they moved west from other Turkic peoples after the Göktürk empire collapsed, and because the majority of the areas in which they inhabit today (except Turkmenistan and the Turkmen Sahra) are west of the Caspian Sea, while those referred to as "Eastern Turks" live east of the Caspian Sea. The founders of the Ottoman Empire were also Oghuz Turks.

In the 9th century, the Oghuz Turks from the Aral steppes drove the Pecheneg Turks, of the Emba region and the Ural River, 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—a branch of the Kimaks of the middle Irtysh or of the Ob—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).