Seljuks, Or Seljooks, a Turco-Tartaric tribe, of the Uiguric division of the race, originally inhabiting the plain N. of the Caspian sea. They received their name from Seljuk, one. of their chiefs, under whose guidance in the 10th century they settled in Bokhara, and embraced Mohammedanism. His grandson Togrul Beg received the title of sultan, conquered successively Khorasan and other Persian provinces, and in 1055 made himself master of Bagdad, which he occupied nominally as the servant and guardian of the caliph, but really with sovereign power, under the title of emir el-omra or "commander of the faithful." He died in 1063, and was succeeded by his nephew Alp Arslan, famous for his victories over Roma-nus Diogenes. (See Alp Arslan.) He was succeeded in 1072 by his son Malek Shah, who made Ispahan his capital, and extended his dominions from the frontiers of China to the neighborhood of Constantinople. The ill treatment of the Christian pilgrims to Jerusalem by his viceroys was the immediate cause of the crusades.

On his death in 1092 the succession to the throne was disputed by his brother and his four sons, and a series of civil wars ensued, which ended in the partition of the Seljukian empire among four branches of the imperial family, of which the principal dynasty ruled in Persia, and the three younger dynasties at Kerman, Damascus, and Iconium. The last named, whose kingdom was called by the orientals the sultanate of Roum (that is, of the Romans), outlasted the others, enduring till the end of the 13th century, when it was succeeded by that of the Ottomans. During the greater part of the 13th century the Seljukian sultans were tributary to the Mongol emperors, who deposed and put them to death at pleasure.