or FLA'VIUS, SU'BRIUS, tribune in the Praetorian guards, and most active agent in the conspiracy against Nero, A. D. 66, which, from its most distinguished member, was called Piso's conspiracy. Flavus proposed to kill Nero while singing on the stage, or amidst the flames of his palace. He was said to have intended to make away with Piso also, and to offer the empire to Seneca, the philosopher, since such a choice would justify the conspirators, and it would be to little purpose to get rid of a piper, if a player--for Piso, too, had appeared on the stage--were to succeed him. The plot was detected. Flavus was betrayed by an accomplice and arrested, and, after some attempts at excuse, gloried in the charge. He was beheaded, and died with firmness. Dio Cassius calls him Σούβιος Φλάβιος, and in some MSS. of Tacitus the name is written Flavius. (Tac. Ann. 15.49, 50, 58, 67; D. C. 62.24.)