born of an obscure family at Capua, rose by his oratorical talents to distinction at Rome in the reigns of Claudius, Nero, and Vespasian. (Dialog. de Orator. 8 ; Schol. Vet. ad Juv. Sat. 4.81.) On the deposition of L. Silanus, A. D. 49, Marcellus was appointed to the vacant praetorship, which, however, was so nearly expired that he held it only a few days, or perhaps hours. (Tac. Ann. 12.4; comp. Suet. Cl. 29.) At the beginning of Nero's reign Marcellus was proconsul of a portion of Asia Minor, probably of Pamphylia, for in A. D. 57, after his return to Rome, the Lycians, who since their annexation by Claudius, in A. D. 43, were attached to that province (D. C. 60.17), accused him of malversation. His eloquence, or rather his wealth, procured an acquittal, and some of his accusers were banished as the authors of an unfounded and frivolous charge. (Tac. Ann. 13.33.) Marcellus now became one of the principal delators under Nero. He was able, venal, and unscrupulous, and he accordingly acquired wealth, influence, and hatred. In A. D. 66, he seconded Cossutianus Capito [CAPITO COSSUTIANUS] in the impeachment of Thrasea Paetus, and for his exertions received from Nero an extravagant fee (id. Ann. 16.23, 26, 28, 33). The fortunes of Marcellus were for a time shaken by Nero's death. He became in turn the object of attack -- by Helvidius Priscus, Thrasea's son-iin-law, as a delator, and by Licinius Caecina, a partisan of Otho's [CAECINA, No. 10], as a favourer of Vitellius, A. D. 69. (Tac. Hist. 2.53, 4.6.) His contest with Helvidius Priscus in the senate, A. D. 70, when the mode of appointing the delegates to Vespasian in Egypt was debated, is sketched by Tacitus (Tac. Hist. 4.6-8) with a brevity that leaves nothing obscure. From Helvidius and Caecina Marcellus escaped as much through the dislocation of the times, the feebleness of the emperor, and the fears of the senate, as by his own eloquence and address. But Helvidius assailed him a third time on the old charge of delation, and, on this occasion, his talents, backed indeed by his strong interest with Mucianus and Domitian, rescued him. (Dialog. de Orat. 8, comp. 5.) He ingratiated himself with the elder Vespasian also, and was nearly as powerful for a while under the Flavian house as under Claudius and Nero. But towards the close of Vespasian's reign, A. D. 79, Marcellus, from what motives is unknown, engaged in Alienus Caecina's conspiracy against the emperor [CAECINA ALIENUS]. Caecina was assassinated, Marcellus was tried, convicted, and, unable to withstand the long-stored hatred of the senators, destroyed himself. (D. C. 66.16.) The character of Marcellus is drawn by the author of the Dialogue de Oratoribus (5, 8, 13); his eloquence was his only merit, and he abused it to the worst purposes.

A coin of the town of Cyme in Aeolia bears on its obverse, *A*N*Q*G. *E*P*I*W. *M*A*P*K*E*A*A*W. *T. *K*Y., and refers, probably, to the period of his proconsulate of Pamphylia. (Eckhel, Doct. Num. Vet. vol. ii. p. 493.)