What is "tughril"

Tughril (; full name: Rukn al-Dunya wa al-Din Abu Talib Muhammad Toghrul-Beg ibn Mikail) also spelled Toghrul I, Tugril, Toghril, Tugrul or Toghrïl Beg; (990 – September 4, 1063) was the Turkic founder of the Seljuk Empire, ruling from 1037 to 1063. Tughril united the Turkic warriors of the Great Eurasian Steppes into a confederacy of tribes, who traced their ancestry to a single ancestor named Seljuq, and led them in conquest of eastern Iran. He would later establish the Seljuq Sultanate after conquering Persia and retaking the Abbasid capital of Baghdad from the Buyid dynasty in 1055. Tughril relegated the Abbasid Caliphs to state figureheads and took command of the caliphate's armies in military offensives against the Byzantine Empire and the Fatimid Caliphate in an effort to expand his empire's borders and unite the Islamic world.