was an independent Moorish chief, not belonging to the Roman province of Mauritania. He served, however, with a body of Moorish cavalry in the Roman army, but in consequence of some offence which he had committed, he was dismissed from the service with disgrace. At a later time, A. D. 101, when Trajan was going to carry on war against the Dacians, and was in want of Moorish cavalry, Quietus offered his services again of his own accord, and was received with welcome by the emperor. In this war, and still more in the Parthian war, which began in A. D. 114, Quietus gained great distinction, and became one of the favourite generals of Trajan. He took the towns of Nisibis and Edessa, and subdued the Jews, against whom he had been sent. Trajan made him governor of Judaea, and rewarded him still further by raising him to the consulship in A. D. 116 or 117. His name does not appear in the Fasti, and he must, therefore, have been only one of the consules suffecti for the year. The honours conferred upon him by Trajan excited much envy; but so great a favourite was he with the emperor, that there was a report, if we may believe Themistius, that Trajan destined him as his successor. Quietus is represented on Trajan's column at the head of his Moors. After Trajan's death he returned to his native country, but he was suspected by Hadrian of fomenting the disturbances which then prevailed in Mauritania. He was first deprived of the tribes whom he governed, and was then summoned to Rome. There he was accused of entering into a conspiracy against Hadrian's life, and was murdered on a journey, probably while travelling from Mauritania to Rome. (D. C. 68.8, 22, 30, 32, 69.2; Themistius, Orat. xvi. p. 205, ed. Petavius, Paris, 1684; Euseb. Hist. Eccl. 4.2, with the note of Valesius; Spartian. Hodr. 5, 7; Amm. Marc. 29.5.)