Life
Tughril Beg (reigned 1037–1063), grandson of Seljuk, united the Oghuz Turkmen and conquered Persia, defeating the Ghaznavids at Dandanaqan (1040). In 1055 he entered Baghdad, freeing the Abbasid caliph from Buyid control and receiving the title of sultan as the caliphate's temporal protector and champion of Sunni Islam against the Shia Buyids and Fatimids. He founded the Great Seljuk Empire that would dominate the Islamic east for over a century.