Gaius Sosius was a Roman general and politician.

Gaius Sosius was elected quaestor

Quaestor

A Quaestor was a type of public official in the "Cursus honorum" system who supervised financial affairs. In the Roman Republic a quaestor was an elected official whereas, with the autocratic government of the Roman Empire, quaestors were simply appointed....

 in 66 BC and praetor

Praetor

Praetor was a title granted by the government of Ancient Rome to men acting in one of two official capacities: the commander of an army, usually in the field, or the named commander before mustering the army; and an elected magistratus assigned varied duties...

 in 49 BC. Upon the start of the civil war

Caesar's civil war

The Great Roman Civil War , also known as Caesar's Civil War, was one of the last politico-military conflicts in the Roman Republic before the establishment of the Roman Empire...

, he joined the party of the Senate sometimes called optimates

Optimates

The optimates were the traditionalist majority of the late Roman Republic. They wished to limit the power of the popular assemblies and the Tribunes of the Plebs, and to extend the power of the Senate, which was viewed as more dedicated to the interests of the aristocrats who held the reins of power...

 by modern scholars (even though the term belongs to the era of Sulla and Marius

Marius

Marius may refer to:* Marius , a male given name, a Roman family name, and a modern surname** Gaius Marius, Roman general and statesman.* Marius , on the Moon* Marius Hills, on the Moon* Marius , written by Marcel Pagnol...

). Upon the flight of Pompey

Pompey

Gnaeus Pompeius Magnus, also known as Pompey or Pompey the Great , was a military and political leader of the late Roman Republic...

 to Greece, Sosius returned to Rome and submitted to Julius Caesar

Julius Caesar

Gaius Julius Caesar was a Roman general and statesman and a distinguished writer of Latin prose. He played a critical role in the gradual transformation of the Roman Republic into the Roman Empire....

.

After the assassination of Caesar, Sosius joined the party of Mark Antony

Mark Antony

Marcus Antonius , known in English as Mark Antony, was a Roman politician and general. As a military commander and administrator, he was an important supporter and loyal friend of his mother's cousin Julius Caesar...

, by whom in 38 BC he was appointed governor of Syria

Syria (Roman province)

Syria was a Roman province, annexed in 64 BC by Pompey, as a consequence of his military presence after pursuing victory in the Third Mithridatic War. It remained under Roman, and subsequently Byzantine, rule for seven centuries, until 637 when it fell to the Islamic conquests.- Principate :The...

 and Cilicia

Cilicia

In antiquity, Cilicia was the south coastal region of Asia Minor, south of the central Anatolian plateau. It existed as a political entity from Hittite times into the Byzantine empire...

 in the place of Publius Ventidius. As governor, Sosius was commanded by Antony to support Herod

Herod the Great

Herod , also known as Herod the Great , was a Roman client king of Judea. His epithet of "the Great" is widely disputed as he is described as "a madman who murdered his own family and a great many rabbis." He is also known for his colossal building projects in Jerusalem and elsewhere, including his...

 against Antigonus the Hasmonean

Antigonus the Hasmonean

Antigonus II Mattathias was the last Hasmonean king of Judea. He was the son of King Aristobulus II of Judea...

, 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 services, he was awarded a triumph in 34 BC, and he became consul

Consul

Consul was the highest elected office of the Roman Republic and an appointive office under the Empire. The title was also used in other city states and also revived in modern states, notably in the First French Republic...

 along with Gnaeus Domitius Ahenobarbus

Gnaeus Domitius Ahenobarbus (consul 32 BC)

Gnaeus Domitius Ahenobarbus was a general and politician of ancient Rome in the 1st century BC.-Life:Ahenobarbus was captured with his father, Lucius Domitius Ahenobarbus, at Corfinium in 49 BC, and was present at the Battle of Pharsalus in 48 BC, but did not take any further part in the war...

 as his colleague in 32 BC. When civil war

Final war of the Roman Republic

The final war of the Roman Republic, also known as Antony's civil war or the war between Antony and Octavian, was the last of the Roman civil wars of the republic, fought between Cleopatra and Octavian...

 broke out between Antony and Octavian

Augustus

Augustus ;23 September 63 BC – 19 August AD 14) is considered the first emperor of the Roman Empire, which he ruled alone from 27 BC until his death in 14 AD.The dates of his rule are contemporary dates; Augustus lived under two calendars, the Roman Republican until 45 BC, and the Julian...

, 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 he managed to defeat the squadron of Taurius Rufus – according to Dio 50.14 – and put it to flight, but when the latter was reinforced by Marcus Agrippa, Sosius's ally Tarcondimotus – the king of Cilicia – was killed and Sosius himself was forced to flee. Dio mistakenly suggests that Sosius died as well, but later affirms he was alive at the battle of Actium

Battle of Actium

The Battle of Actium was the decisive confrontation of the Final War of the Roman Republic. It was fought between the forces of Octavian and the combined forces of Mark Antony and Cleopatra VII. The battle took place on 2 September 31 BC, on the Ionian Sea near the city of Actium, at the Roman...

. At Actium, Sosius commanded the left wing of the fleet. After the battle, from which he managed to escape, his hiding place was detected and Sosius was captured and brought before Octavian but, at the intercession of Lucius Arruntius

Lucius Arruntius

Lucius Arruntius was a Roman admiral. He saw action during the War with Sextus Pompeius, and the war of Mark Antony and Augustus. He is most notable for his participation during the Battle of Actium, where he was in command of victorious Augustus' central division...

, Octavian pardoned him. He returned to Rome and completed his building project on the temple of Apollo Medicus

Temple of Apollo Sosianus

The Temple of Apollo Sosianus is a Roman temple dedicated to Apollo in the Campus Martius, next to the Theatre of Marcellus and the Porticus Octaviae, in Rome, Italy...

 (begun in 34 BC), dedicating it in Octavian's name.

Sosius attended the Ludi Saeculares in 17 according to an inscription CIL 6.32323 = ILS 5050 as a quindecimvir. According to Gaius Stern, Sosius appears on the Ara Pacis

Ara Pacis

The Ara Pacis Augustae is an altar to Peace, envisioned as a Roman goddess...

 within the College of the quindecimviri sacris faciundis.