ONMI'ADES (Omaiades, or Ommeyades), a dynasty (deriving its name from an ances tor, Ommeyah) which succeeded to the Arabian caliphate on the death of Ali, the fourth caliph after Mohammed, and possessed it till superseded by the Abbasides (q.v.) in 750. Moawiyali, the founder of the dynasty, was the son of Abu-Sofiau, who defeated Moham med at Beeler, and his mother was the notorious Ilinda. After the death of Othman the third caliph, Moawiyali, who was his cousin, claimed the throne, and during the whole of Ali's reign ruled over the western provinces of Syria and Egypt; but it was not till the death of that caliph, and the abdication of his son Hassan in 661, that authority was fully recognized. In that year he transferred the seat of the caliphate to Damascus; Nada having been the residence of Ali, and Medina of the first three caliphs. The Arabs continued to extend their conquests during his reign; the Turks in Khorassan were subdued, Turkestan invaded, and several important acquisitions made in Asia Minor. But besides aggrandizing his empire, the caliph neglected no means of consoli dating it, and partly for this reason he made the succession hereditary, and caused his son YEzna (680-83) to be recognized as his heir. The reigns of Yezid and his succes sors, Moawraan IL (683) and MEnallas I., formerly the traitorous secretary of the caliph Othntan (683-85), are devoid of importance, as their sway extended only over Syria and Palestine. ABDULAIELEK (685-705), an able and warlike prince, after a long and varying struggle of eight years, succeeded in rendering himself undisputed ruler of the Moham medan world (692), but the latter part of his reign was much disturbcd by rebellions in the eastern provinces. He was the first caliph who interested himself in the promotion of liberal knowledge, by causing the most celebrated poetical and other works of the Persians to be translated into Arabic; and under his reign coined money was first intro duced. It was to this prince that his court-fool related the celebrated fabulous conver sation between the owl of Bassora and that of Mosul. Four of his sons, Wamo I. (705 16), SHUMAN (716-17), YEZID II. (720-23), and HESIDIM (723-42), successively occupied the throne, and a fifth son, Mosslemali, was, front his great military abilities and zealous devotion to the interests of his brothers, the terror of all their enemies, both domestic and foreign. Under Walid, the Ommiade caliphate reached the summit of its power and grandeur; northern Africa (709), and Spain (712), Turkestan (707), and Galatia (710) were conquered; while toward the close of his reign, his empire was extended even to the Indus. Tlie slender structure of the minaret was now for the first time introduced into mosque architecture. OMAn II. (717-20), who, in the justice and mildness of his government, surpassed the whole of the race of Ommeyah, was appointed to succeed Sunman; but having excited discontent among his relatives, by suppressing the formula of malediction, which had hitherto been regularly pronounced at all public ceremonies against Ali and his descendants, he was During his reign, Mosslemah had completed the conquest of Asia Minor, and even compelled the emperor Leo to sulmit to the humiliation of walking beside his horse through the principal streets of Constanti nople itself, and paying a large ransom (equivalent to about £140,C00) for his capital.
Hesham, though like his immediate predecessor, fond of pleasure, possessed all the qualities necessary for a sovereign. The Greeks, who still strove for the possession of Asia Minor, were repeatedly defeated: the fierce Turks of northern Persia and Turkestan, were kept in stern-subjection; and the civil affairs of the empire carefully and strictly administered. The death of Mosslemah, the champion of the Ommiade dynasty, seems to have been the signal for insurrection; the descendants of All raised the standard of revolt, and no sooner were they subdued than Ibrahim, the fourth in direct descent from Abbas the uncle of Mohammed, solemnly invested the celebrated Abu-Mosslem (stated to be a descendant of Koderz, one of the most distinguished heroes of Firdusi's admired work the Shah-nameh) with the arduous duty of enforcing his long-agitated claims to the throne. During this reign the progress of Arab conquest in western Europe wi:s checked by Charles Martel, who inflicted upon the Arabs a severe defeat at Tours (732), and almost annihilated their army at Narbonne (736). The reigns of Wamo II. (742-43), YEZID III. (743-44), and IBRAHIM (744), though of ephemeral duration, were long enough to produce a complete disorganization of the empire; and though MEawILN IL (744-50), the next and last caliph of the house of Ommeyah, was both an able and politic ruler, and a skillful warrior, the declining fortune of his family was beyond remedy. Alm-Mosslem, who had published the claims of the Abbasides amidst the ruins of Meru in 747. took the field at the head of a small hut zealous band, and carried the black flag of the Abba sides from victory to vic!orta tillbefore the close of the following year the whole IP( Khorassan acknowledged hiS authority. Irak was subdued in 749; and though Ibrahim the Abbaside claimant was seized by Merwttn, and executed in the same year, his brother ..1.13n1-..lbbas succeeded to his claims, and the unfortunate caliph, defeated in two engage ments, tied to Egypt (750), whither he was pursued and slain. Abdallah, the uncle of the successful claimant, treacherously invited the remaining members of the house of Ornineyall to a conference, and ordered massacer of them. Two only escaped: the one to the s.e. of Arabia, where he was recognized as caliph, and his descendants reigned till the 16th c. ; the other, Abderrahman, tOSpain, where he founded the caliphate of Cordova.