5. P.Sestius, also written P. SEXTIUS in many MSS. and editions of Cicero, the son of No. 4, was defended by Cicero in B. C. 56, in the , an oration which is extant. Although the ancestors of Sestius had not gained any distinction in the state he formed matrimonial alliances with two of the noblest families at Rome. His first wife was Postumia, the daughter of C. Postumius Albinus, by whom he had two children, a daughter and a son. On the death of Postumia he married a second time Cornelia, the daughter of L. Scipio Asiaticus, who was consul in B. C. 83, when his troops deserted to Sulla. He lived in exile at Massilia, where his daughter and Sestius paid him a visit. Sestius began public life in B. C. 63 as quaestor to C. Antonius, Cicero's colleague in the consulship. He warmly co-operated with Cicero in the suppression of the Catilinarian conspiracy. He defeated at Capua the attempts of the conspirators, and from thence hastened to Rome at Cicero's summons, who feared fresh commotions when the new tribunes entered upon their office on the 10th of December. But when this danger passed away, Sestius followed C. Antonius into Etruria, and it was chiefly owing to him and M. Petreius that Catiline's army was defeated. On the conclusion of the war, he accompanied Antonius to Macedonia as proquaestor, and there distinguished himself, accerding to Cicero, by his upright administration. In B. C. 57, he was tribune, and took an active part in obtaining Cicero's recall from banishment. Like Milo, lie kept a band of armed retainers to oppose P. Clodius and his partizans; and he was wounded in one of the many affrays which were then of daily occurrence in the streets of Rome. Cicero, on his return to Rome in the autumn of this year, returned him thanks in the senate and also before the people for his exertions on his behalf. Still Cicero felt himself aggrieved by the way in which Sestius had proposed his recal, and still more because the latter had not taken sufficient care to indemnify him for the loss of his property, which Clodius had confiscated. A coolness thus arose between Cicero and Sestius. Still this did not affect the relations in which Sestius and Clodius stood to one another. Sestius was anxious to briug Clodius to trial before he was elected to the aedileship; but he did not succeed in this : Clodius became aedile in B. C. 56, and caused two accusations to be brought against his enemy. Cn. Nerius accused him of bribery at the elections, and M. Tullius Albinovanus of Vis during his tribunate. The former accusation appears to have been dropt; but lie as brought to trial for vis before the court presided over by the praetor M. Aemilius Scaurus. He was defended by M. Crassus and Hortensius, as well as by Cicero, the latter of whom came forward on his behalf contrary to the expectation of many but although Cicero thought he had grounds of offence against Sestius, he did not like to incur the reproach of ingratitude which would have been brought against him, if he had refused to assist the tribune who had proposed his recal from banishment; and as Pompey was still at enmity with Clodius, he required Cicero to undertake the defence of the accused. Cicero could not deny the fact that Sestius had broken the public peace; but he maintained that his client deserved praise and not punishment, because he had taken up arms in defence of himself, the saviour of the Roman state, and consequently in defence of the state itself. Sestius was unanimously acquitted on the 14th of March, chiefly, no doubt, in consequence of the powerful influence of Pompey. (Cic. pro P. Sestio, passim; Cic. in Cat. 1.8, ad Fam. 5.6, ad Att. 3.19, 20, 23, ad Q. Fr. 1.4, ad Att. 4.3, pro Mil. 14, post Red. in Sen. 8, post Red. ad Quir. 6. ad Q. Fr. 2.3, 4; Drumann, Geschichtc Roms. vol. v. p. 664, &c.)

In B. C. 53, Sestius was praetor, and it appears from a passage of Cicero, in which he speaks (ad Fam. 5.20.5) of Sestius having taken some money which L. Mescinius Rufus, Cicero's quaestor in Cilicia, had deposited in a temple, that Sestius afterwards obtained the province of Cilicia as propraetor. On the breaking out of the civil war in B. C. 49, Sestius was with Pompey in Italy, and wrote Pompey's reply to the propositions of Caesar, at which Cicero expresses great vexation on account of the miserable style in which Sestius was accustomed to write, and declares that he never read any thing σηστιωδέστερον than the document which went forth in Pompey's name (Cic. Att. 7.17, comp. ad Fam. 7.32, " omnia omnium dicta, in his etiam Sestiana, in me conferri ais "). He subsequently deserted the Pompeian party and joined Caesar, who sent him, in B. C. 48, into Cappadocia, where it appears that he remained some time. He was alive in B. C. 43, as appears from Cicero's correspondence. (Hirt. B. Alex. 34 ; Cic. Att. 13.2, 7, 15.17, 27 16.4,ad Fam. 13.8.)