Gaius Sosius (fl. 66–17 BC) was a Roman general and politician.
Gaius Sosius was elected quaestor in 66 BC and praetor in 49 BC. Upon the start of the civil war, he joined the party of the Senate sometimes called optimates by modern scholars (even though the term belongs to the era of Sulla and Marius). Upon the flight of Pompey to Greece, Sosius returned to Rome and submitted to Julius Caesar.
After the assassination of Caesar, Sosius joined the party of Mark Antony, who in 38 BC appointed him governor of Syria and Cilicia in the place of Publius Ventidius. As governor, Sosius was commanded by Antony to support Herod against Antigonus the Hasmonean, when the latter was in possession of Jerusalem. In 37 BC, he advanced against Jerusalem and after he became master of the city, Sosius placed Herod upon the throne.
In return for this service, he was awarded a triumph in 34 BC, and in 32 BC he became consul along with Gnaeus Domitius Ahenobarbus. When civil war broke out between Antony and Octavian, Sosius espoused the cause of Antony and violently attacked Octavian in the senate, for which he was forced to flee to the east.
In 31 BC, Sosius commanded a squadron in Mark Antony's fleet with which (according to Dio 50.14) he managed to defeat the squadron of Taurius Rufus and put it to flight, but, when the latter was reinforced by Marcus Agrippa, Sosius's ally Tarcondimotus I, the king of Cilicia, was killed and Sosius himself was forced to flee. At the Battle of Actium, Sosius commanded the left wing of the fleet. After the battle, from which he managed to escape, Sosius' hiding place was found and he was captured and brought before Octavian but, at the intercession of Lucius Arruntius, Octavian pardoned him. He returned to Rome and completed his building project on the temple of Apollo Medicus (begun in 34 BC), dedicating it to Octavian's name.
It is unknown if Sosius had sons, but two daughters are known: Sosia and Sosia Galla, possibly by an Asinia, a Nonia or an Aelia, based on the name of Sosia Galla. However, the name reappears with Q. Sosius Senecio (consul in 99 and 107) and Saint Sossius (275-305 AD).
Sosius attended the Ludi Saeculares in 17 according to an inscription CIL 6.32323 = ILS 5050 as a quindecimvir. Sosius appears on the Ara Pacis within the College of the quindecimviri sacris faciundis.
- Gaius Stern, Women Children and Senators on the Ara Pacis Augustae, University of California Berkeley dissertation 2006, page 353, n.88
- Some Arval Brethren by Ronald Syme.
- Gaius Stern, Women Children and Senators on the Ara Pacis Augustae
- Appian, 5. C. v. 73;
- Cic. ad Ait. viii. 6, ix. 1;
- Dio Cass. xlix. 22, xlix. 41, I. 2, 14, li. 2, Ivi. 38;
- Joseph. Ant. xiv. 15, 16, B. J. i. 17—18;
- Plut. Ant. 34;
- Suet. Aug. 17;
- Tac. Hist. v. 9;
- Vell. Pat. ii. 85, 86.
- Martha Hoffman Lewis, The Official Priests of Rome under the Julio-Claudians. A Study of the Nobility from 44 B.C. to 68 A.D., Rome 1955.
| Consul of the Roman Republic
With: Cn. Domitius Ahenobarbus
L. Cornelius Cinna
M. Valerius Messalla