The Seljuk empire was founded by Tughril Beg (990–1063) and his brother Chaghri Beg (989–1060) in 1037. From their homelands near the Aral Sea, the Seljuks advanced first into Khorasan and then into mainland Persia, before eventually capturing Baghdad and conquering eastern Anatolia. Here the Seljuks won the battle of Manzikert in 1071 and conquered most of Anatolia from the Byzantine Empire, which became one of the reasons for the First Crusade (1095–1099). Starting from 1140s, the Seljuk empire declined, and was eventually replaced by the Khwarazmian Empire in 1194.