a freedman of Galba, who was arrested by Nero on the first tidings of his patron's defection, but released when the revolt against the emperor extended to Rome. Having given up Nero's body to his freed-women for sepulture, Icelus hurried from Rome to Clunia in Hispania Tarraconensis with the news of Nero's death, and of Galba's nomination to the empire by the army and the senate, A. D. 68. His earnest representations removed Galba's fears, and he rewarded Icelus with the rank and golden ring of an eques, and with the honorary addition of Marcianus to his former name. Icelus was the most ignoble, the most powerful, and not the least rapacious of Galba's freedmen and favourites. (Plut. Galb. 7; comp. Dio Cass. Ixiv. 2.) In the parties that divided the imperial council he supported Cornelius Laco, the praetorian prefect [LACO], and with him opposed the adoption of M. Salvius Otho. After Galba's murder, which was perhaps accelerated by Icelus' advice, Icelus was executed by Otho's command as a libertinus, with-out regard to his new equestrian dignity. (Tac. Hist. 1.13, 33, 37, 46, 2.95; Suet. Nero 49, Galb. 14, 22.)
[W.B.D]A Dictionary of Greek and Roman biography and mythology
Smith, William
A Dictionary of Greek and Roman biography and mythology. William Smith, LLD, ed. 1890