17. L.CassiusLonginus, of unknown descent, probably the same as the L. Cassius whom Cicero names among the judges of Cluentius (pro Cluent. 38), was, along with Cicero, one of the competitors for the consulship for the year B. C. 63. At the time he was considered to be rather deficient in abilities than to have any evil intentions; but a few months afterwards he was found to be one of Catiline's conspirators, and the proposer of the most dreadful measures. He undertook to set the city on fire; and he also carried on the negotiation with the ambassadors of the Allobroges, but was prudent enough not to give them any written document under his seal, as the others had done. He left Rome before the ambassadors, and accordingly escaped the fate of his comrades. He was condemned to death in his absence, but whether he was apprehended and executed afterwards we do not know. (Ascon. in Tog. Cand. p. 82, ed. Orelli; Appian, App. BC 2.4; Sal. Cat. 17, 44, 50; Cic. Cat. 3.4, 6, 7, pro Sull. 13, 19.)