5. L.ScriboniusLibo, the father-in-law of Sex. Pompey, the son of Pompey the Great, and consul B. C. 34, is first mentioned in B. C. 56, in which year he appears to have been tribune, as supporting Pompey's views in relation to the affairs of Egypt in the case of Ptolemy Auletes. (Cic. Fam. 1.1.) On the breaking out of the civil war in B. C. 49, Libo naturally sided with Pompey, and was entrusted with the command of Etruria. But the rapid approach of Caesar, and the enthusiasm with which he was every where received, obliged Libo to retire from Etruria and join the consuls in Campania, from whence he subsequently proceeded with the rest of the Pompeian party to Brundisium. While here Caesar sent to him Caninius Rebilus, who was an intimate friend of Libo, to persuade him to use his influence with Pompey to effect a reconciliation; but nothing came of this negotiation. (Flor. 4.2.1; Lucan, 2.461; Cic. Att. 7.12, 8.11, b; Caes. Civ. 1.26.)

Libo accompanied Pompey to Greece, and was actively engaged in the war that ensued. He and M. Octavius were placed over the Liburnian and Achaean fleets, serving as legates to Bibulus, who had the supreme command of the Pompeian fleet. They were very successful against Caesar's generals in Dalmatia; Dolabella they drove out of the country, and C. Antonius they not only defeated but made prisoner. (Caes. Civ. 3.5; D. C. 12.40; Florus, 4.2.31; Oros. 6.15.) Libo subsequently joined Bibulus; and, on the death of the latter shortly afterwards, the chief authority in the fleet appears to have devolved upon him, although no one was expressly appointed to the supreme command. With fifty ships he appeared before Brundisium, in order to blockade the place strictly, as M. Antony was still there with part of Caesar's troops, waiting for an opportunity to cross over to Greece. But having suffered a repulse from Antony, and being prevented by the cavalry of the latter from obtaining any water, Libo was obliged to retire from the place, and Antony soon afterwards escaped his vigilance and joined Caesar in Greece. (Caes. Civ. 3.15, 16, 18, 23, 24; D. C. 41.48.)

We hear nothing more of Libo for some time, but he probably did not make his submission to Caesar after the battle of Pharsalia, but united himself to those of his party who continued in arms. At the death of the dictator in B. C. 44, we find him in Spain with his son-in-law Sex. Pompey, on whose behalf he wrote to the ruling party at Rome. (Cic. Att. 16.4.) He continued with Pompey in the civil wars which followed, and is specially mentioned, in B. C. 40, as one of the persons of high rank who was commissioned to conduct to Antony in the East his mother Julia, who had taken refuge with Sex. Pompey in Sicily after the Perusinian war. This mission alarmed Octavian. He feared that Pompey, who was now decidedly master of the sea, should unite with Antony to crush him; and, in order to gain the favour of the former and of his father-in-law Libo, he proposed, on the advice of Maecenas, to marry Libo's sister, Scribonia, although she was much older than himself, and had been married twice before. The marriage shortly after took place, and paved the way for a peace between the triumvirs and Pompey. This was negotiated in the following year (B. C. 39) by Libo, who crossed over from Sicily to Italy for the purpose, and it was finally settled at Misenum. When the war was renewed in B. C. 36, Libo for a time continued faithful to Pompey, but, seeing his cause hopeless, he deserted him in the following year. In B. C. 34, he was consul with M. Antony, as had been agreed at the peace of Misenum. As his name does not occur again in history, he probably died soon afterwards. (Appian, App. BC 5.52, 53. 69-73, 139; D. C. 48.16, 49.38.)