is mentioned for the first time in B. C. 61, during the transactions against P. Clodius for having violated the sacra of the Bona Dea. On that occasion he joined Cato, whose sternness he imitated throughout life, in his attacks upon the consul Piso for defending Clodius, and displayed great zeal in the matter. The year after, he accused Metellus Scipio Nasica, probably of bribery. Cicero defended the accused, at which Favonius was somewhat offended. In the same year he sued, a second time, for the tribuneship, but he does not appear to have succeeded, for there is no evidence to prove that he was invested with that office, and Caesar, Pompey, and Crassus, who at the end of the year concluded their treaty, and were well aware that Favonius, although he was harmless, might yet be a very troublesome opponent, probably exerted their influence to prevent his gaining his end. About that time Pompey was suffering from a bad foot, and when he appeared in public with a white bandage round his leg, Favonius, in allusion to his aiming at the supremacy in the Roman republic, remarked that it was indifferent in what part of the body the royal diadem (bandage) was worn. It should be remarked that Favonius, although he belonged to the party of the Optimates, was yet a personal enemy of Pompey. In B. C. 59, when J. Caesar and Bibulus were consuls, Favonius is said to have been the last of all the senators that was prevailed upon to sanction the lex agrarian of Caesar, and not until Cato himself had fielded. In B. C. 57, when Cicero proposed that Pompey should be entrusted with the superintendence of all the supplies of corn, Favonius was at the head of the opposition party, and became still more indignant at the conduct of the tribune Messius, who claimed almost unlimited power for Pompey. When Ptolemy Auletes, the exiled king of Egypt, had caused the murder of the ambassadors whom the Alexandrians had sent to Rome, Favonius openly charged him in the senate with the crime, and at the same time unmasked the disgraceful conduct of those Romans who had been bribed by the king. In the year following, when Pompey was publicly insulted during the trial of Milo, Favonius and other Optimates rejoiced in the senate at the affront thus offered to him. In the second consulship of Pompey and Crassus, in B. C. 55, the tribune Trebonius brought forward a bill that Spain and Syria should be given to the consuls for five years, and that Caesar's proconsulship of Gaul should be prolonged for the same period. Cato and Favonius opposed the bill, but it was carried by force and violence. In B. C. 54, Favonius, Cicero, Bibulus, and Calidius spoke in favour of the freedom of the Tenedians. In the year following Favonius offered himself as a candidate for the aedileship, but was rejected. Cato, however, observed, that a gross deception had been practised in the voting, and, with the assistance of the tribunes, he caused a fresh election to be instituted, the result of which was that his friend was invested with the office. During the year of his aedileship, he left the administration of affairs and the celebration of the games to his friend Cato. Towards the end of the year, he was thrown into prison by the tribune, Q. Pompeius Rufus, for some offence, the nature of which is unknown ; for according to Dio Cassius, Rufus imprisoned him merely that he might have a companion in disgrace, having himself been imprisoned a short time before; but some think, and with greater probability, that it was to deter Favonius from opposing the dictatorship of Pompey, which it was intended to propose. In B. C. 52, Cicero, in his defence of Milo, mentions Favonius as the person to whom Clodius was reported to have said, that Milo in three or four days would no longer be among the living. The condemnation of Milo. however, took place, notwithstanding the exertions to save him, in which Cato and Favonius probably took part. In 51 Favonius sued for the praetorship, but in vain; as, however, in 48 he is called praetorius, it is possible that he was candidate for the same office in the year 50 also, and that in 49 he was invested with it. In this year he and Cato opposed the proposal that a supplicatio should be decreed in honour of Cicero, who was well disposed towards both, and who appears to have been greatly irritated by this slight.

The civil war between Caesar and Pompey broke out during the praetorship of Favonius, who is said to have been the first to taunt Pompey by requesting him to call forth the legions by stamping his foot on the ground. He fled at first with the consuls and several senators to Capua, and was the only one who would not listen to any proposals for reconciliation between the two rivals; but not withstanding his personal aversion to Pompey. he joined him and the Optimates, when they went over to Greece. In B. C. 48. we find him engaged in Macedonia, under Metellus Scipio, and during the ltter's absence in Thessaly, Favonius, who was left behind on the river Haliacmon with eight cohorts, was taken by surprise by Domitius Calvinus, and was saved only by the speedy return of Metellus Scipio. Up to the last moment Favonius would not hear of any reconciliation. After the unfortunate issue of the battle of Pharsalus, Favonins, however, acted as a faithful friend towards Pompey: he accompanied him in his flight, and shewed him thegreatest kindness and attention. After the death of Ponpey, he returned to Italy, and was pardoned by J. Caesar, in whose supremacy he acquiesced, having gained the conviction that monarchy was better than civil war. For this reason the conspirators against the life of Caesar did not attempt to draw him into their plot; but after the murder was accomplished, he openly joined the conspirators, and went with them to the Capitol. When Brutus and Cassius were obliged to leave Rome, he followed them, and was accordingly outlawed in B. C. 43, by the lex Pedia, as their accomplice. He was, however, a troublesome and importunate ally to the republicans, and in 42, when he presumed to influence Brutus and Cassius at their meeting at Sardis, Brutus thrust the intruder out of the house. In the battle of Philippi Favonius was taken prisoner, and on being led in chains before the conquerors, he respectfully saluted Antony, but indulged in bitter invectivtes against Octavianus, for having ordered several republicans to be put to death. The consequence was, as he might have expected, that he met with the same fate.

M. Favonius was not a man of strong character or principle: his sternness of manner and of conduct was mere affectation and imitation of Cato, in which he went so far as to receive and deserve the nickname of the ape of Cato. The motives for his actions, in all cases where we can trace them, sere passion, personal animosity, and a desire to please Cato, the consideration of the public good having no share in them. His only honourable action is the conduct he showed towards Pompey after his defeat. He and L. Postumius are admirably characterised by the Pseudo-Sallust (ad Caes. 2. p. 275, ed Gerlach) as quasi magnae navis supervacua onera. He seems to have had some talent as an orator, at least we know from Cicero that he spoke in public on several occasions, but no specimen of his oratory has come down to us. (Cic. Att. 1.14, 2.1, 4, 7.1, 15. 15.11, ad Qu. Fr. 2.3, 11, ad Fam. 8.9, 11, pro Mil. 9, 16; V. Max. 6.2.7; Plut. Cat. Mi. 32, 46, Pomp. 60, 67, Brut. 12, 34, Caes. 41; D. C. 38.7, 39.14, 34, &100.40.45, 46.48, 47.49; Caes. Civ. 3.36; Vell. 2.53; Appian, App. BC 2.119, &c.; Suet. Octav. 13.)