Tugrul Bey, is the grandson of Seljuk Bey. When his father Mikail fell martyr in a war, he was brought up in Cend by Seljuk Bey. Upon death of Seljuk Bey in 1000 or 1007 and his uncle Arslan Bey's being taken captive by Gazneli Mahmut, he took the lead of Seljukian dynasty in 1025.
His first years elapsed seeking a country and gathering separated Muslim-Turk nomads. He was first defeated by Shah Melik in 1034 in a war he lost 7 or 8 thousand of his soldiers. He won his first victory against Gazne Ruler Mesut in 1035. He saved Seljukians from being refugees with this victory, and turned them into a state with a country. Tugrul Bey, choosing Nişabur as his capital city, had sermons read in his name with the title of Grand Sultan for the first time in 1038.
Seljukians, who fought Ghaznians occasionally afterwards. With Dandanakan pitched battle of Tugrul bey in 1040, they eliminated the danger of collapse. The capital city was transferred from Nişabur to Rey, which was conquered by Ibrahim Yınal, a commander of Cagri Bey. Abbasi Caliph declared that he "assigned all countries Supreme Being conferred upon him to Tugrul Bey".
Tugrul Bey routed Egyptian Fatimis in 1060 in a way not to allow them to recover once more. Islam world, which was in defense against Byzantium until his period, took the offensive with Tugrul Bey. The first Turkish Sultan entering Anatolia was Tugrul Bey. Prince Hasan, the son of Musa Yabgu, who was Tugrul Bey's uncle was defeated by Byzantines near Zap river in 1048. Ibrahim Yinal and Kutalmış, sent therefore by Tugrul Bey, defeated Byzantine army in Bascan (Hasankale) on 18 September 1049 and took their commander Liparites captive.
Tugrul bey conquered Erciş and Bergri castles and laid his military camp in front of Malazgirt, the key to Anatolia. But Malazgirt was not vouchsafed to Tugrul Bey. Tugrul Bey, who improved Baghdad and Rey, died of the disease he caught on 5 September 1063 Friday.