Seljuks, a division of the Ghuzz confederacy of the Turkish tribes, who were settled on the Jaxartes and in Transoxiana in the 11th century, when they became converts to Islam. Togrul Beg, grandson of a chief named Seljuk (whence the name of the several successive dynasties), severely crippled the empire of Ghazni (1040), and then turning westwards conquered all Persia. Ten years later he marched upon Bagdad, to the assistance of the Abbaside Caliph (q.v.), a mere faintant sovereign, who existed by the favour and protection of a powerful family of the Shiite faith. The head of this family (the Bowides) was, however, the master rather than the protector of the caliph. Him Togrul seized and supplanted; and, being of the orthodox Sunnite faith, he was nominated by the caliph 'Commander of the Faithful.' Dying in 1063, Togrul was succeeded by his nephew Alp-Arslan. This sovereign wrested Syria and Palestine from the rival Fatimite caliph of Egypt, and in 1071 defeated the Byzantine emperor Romanus Diogenes, and captured him. The price of his release was a heavy ransom and the cession of great part of Anatolia or Asia Minor to the Seljuk. Alp-Arslan was stabbed by a captive enemy in distant Turkestan (1072), and was succeeded by his son Malik Shah. His reign is chiefly remarkable for the enlightened rule of his grandvizier, Nizam ul-Mulk, the schoolfellow of Omar Khayyam (q.v.), the poet, and of Hassan ibn Sabbah, the founder of the Assassins (q.v.). This statesman founded a university at Bagdad, an observatory, and numerous schools and mosques, and with the help of his old friend Omar Khayyam revised the astronomical tables and introduced a new era, the Jelalian. After the death of Malik (1092) the extensive empire began to break up into smaller kingdoms. But already during his lifetime, and even that of his predecessors, powerful tributary princes had ruled over separate provinces in Syria (see NUR ED-DIN and SALADIN), in Kerman (beside the Persian Gulf), and in Asia Minor. During the first half of the 12th century the most powerful of these provincial rulers was Sinjar, who governed Khorassan, with Merv for his capital. He spent his life fighting against the Ghaznevids, against the Turkestan chiefs, and latterly against the Mongols. But a stronger and more immediate interest attaches to the province of Syria and that of Asia Minor, or Rum, as the Seljuks preferred to call it. It was the rulers of these two provinces or kingdoms who persecuted the Christian pilgrims and so provoked the Crusades (q.v.), and it was the rulers of the same two kingdoms against whom the crusaders of Europe principally fought. The capital of Rum was fixed at Iconium (Konieh) in the first half of the 12th century. This dynasty reached the acme of its power under Kaikavus (1211-34), who ruled over nearly the whole of Asia Minor and extensive territories in Mesopotamia and northern Persia. During the reign of his son Kaikhosran II. the poet Jelal-ed-Din Rumi flourished and the various orders of dervishes arose; and at the same time the Mongols began to threaten the eastern borders of the state. Indeed from about 1243 the real sovereign power of that part of Asia was in the hands of the Mongol chiefs, Hulagu and his successors, until the rise of the Ottoman princes. These last, Turks like the Seljuks, had retreated westwards before the all-conquering Mongols about the middle of the 13th century, and at the end of it they entered the service of the Seljuk ruler of Asia Minor. After that the name Osmanli or Ottoman soon superseded that of Seljuk as the appellation of the Turkish rulers and ruling classes in Asia Minor. And out of the Ottoman supremacy grew the empire of Turkey (q.v.). The Seljuks, however, had centuries before, whilst they were still settled in Transoxiana, lost a good many of their peculiarly Turkish characteristics and had become 'Turkomans,' i.e. 'Like the Turks;' and with their conversion to Islam they also adopted the Perso-Arabian civilisation and customs, though still retaining their own language as well as using those of the peoples they had conquered.
See De Guignes, Histoire des Huns, &c. (4 vols. 1756-58), and the German translation (by Vullers, 1838) of Mirkhond's Persian History of the Seljuks.