Tughril united many Turkoman warriors of the Central Asian steppes into a confederacy of tribes and led them in conquest of Khorasan and eastern Persia.
However, under Tughril peace and prosperity were brought to the country and to Mesopotamia, a transition that was further reinforced due to the Seljuks' assimilation to Iranian-Muslim culture.
[7] Tughril was born in c. 993,[8] most likely in the Central Asian steppes, where nomadic Oghuz Turks were roaming to find pasture for livestock.
[9] In the following decades, the Seljuks were employed as mercenaries under the warring factions of Transoxiana and Khwarazm, in exchange for pasture for their herds.
Seljuk's son Arslan Isra'il fled to a place near Sarakhs, where he asked Mahmud for permission to settle in the area in return for military aid.
[14] In 1054, Tughril forced the Rawadid ruler of Azerbaijan, Abu Mansur Wahsudan, to acknowledge his authority.
Tughril's name was placed in the khutba (Friday prayer), while a son of Wahsudan, possibly Abu'l-Hayja Manuchihr, was sent as a Seljuk hostage to Khurasan.
Two years later Tughril crushed the rebellion, personally strangling İbrahim with his bowstring and entered Baghdad.
[19][8] The succession was contested by Chaghri Beg's more competent and elder son Alp Arslan, who had ruled Khurasan since his father's death in 1059.
Alp Arslan quickly asserted his authority over the whole empire, becoming the first Seljuk ruler to rule over both Tughril's and Chaghri's lands.
Though his military campaigns inflicted serious damage on the productive forces of many conquered states, they paved the way for the establishment of the first powerful medieval empire of the Turks that linked "the East and the West".
[34] The formation of a vast empire objectively led to important changes in socio-economic, political and cultural life.
Noticeable changes in the life of the Oguz-Turkmen tribes occurred as they settled in Khorasan, Iran, Iraq, Syria, Transcaucasia and Asia Minor.
The old tribal ties broke up; feudal relations received a new incentive for further development, although remnants of archaic institutions remained for a long time.