. The Seljuks played a major role in medieval history by creating a barrier to Europe against the Mongols invaders from the East, defending the islamic world against crusaders from the West, and conquering large parts of the Byzantine Empire. Under Tughril Beg rule, the Seljuks assumed the leadership of the Islamic world by establishing political mastery over the Abbasids caliphate in Baghdad. Tughril Beg ruled great Seljuk Empire until his death in 1063. His nephew Alp Arslan succeeded him as sultan.
. Sultan Alp Arslan became the second ruler of the Great Seljuk Empire in 1063 CE. Sultan Alp Arslan ( the Lion-hearted), opened the gates of Anatolia to Turks in 1071 CE by defeating the Byzantine army. He is remembered for his heroism and war strategies.
. Nasir-ud-Din Mahmud-1 ( 1087–1094 CE ) succeeded Malik shah-1 as sultan, but he did not gain control of the empire built by Malik Shah and Alp Arslan. Mahmud-2' reign ( 1105 - 1118 CE ) is recognized for the extensive administration military, and social and economic reforms. Tughril-3 ( 1169- 1194 CE ) was the last sultan of Seljuk Empire. Ala-ud-Din Tekish, Shah of khwarazmian Empire defeated Tughril-3 and the Seljuk Empire collapsed in 1194 CE.
