praetorian prefect under Claudius I. A. D. 48. He was superseded during the arrest of the empress Messalina by the freedman Narcissus, and deprived of his prefecture in A. D. 52, by Agrippina, who regarded him as a creature of Messalina's, and attached to her son Britannicus. (Tac. Ann. 11.31.33, 12.42.)