This Legion was recruited by Julius Caesar in Cisalpine Gaul in 58 BC for the campaign against the Helvetii, and it would continue to serve under him throughout the Gallic Wars, particularly against the Nervians in 57, and at the sieges of Bourges and Alesia. After serving through the Civil War with Pompey, the soldiers were given their pensions and land in Parma in 45. After Caesar's murder, the Legion was reconstituted by Marcus Lepidus, and handed to Marc Antony, under whom it fought at the Battle of Philippi, and then against Armenia and the Parthians. After the decisive Battle of Actium in 31, Octavian became Emperor Augustus, and the Legion was among those used to occupy Egypt, although it soon garrisoned Syria. In 20, it was one of the Legions that impressed the Parthians to return the eagle standards they'd taken after the slaughter of Crassus at Carrhae in 53. The Legion was one of those that successfully campaigned in the vassal kingdom Armenia, helping to capture the capitals od Artaxata and Tigranocerta in 58-9 AD. After being forced to surrender to Parthians at Rhandeia in 62, and later losing its eagle standard to Jewish Zealots, the Legion regained its reputation in the final phase of the war against the Jews and returned to prominent status. In 75 AD, Emperor Domitian sent the Legion to support the kingdoms of Iberia and Albania, and an inscription found near the Caspian Sea shores mentions its presence there, the farthest point eastward any Roman Legion ever penetrated. In 114, the Legion fought in Trajan's Armenian Campaign, culminating in the annexation of that kingdom. In 134, the Legion defeated the Alan invaders, as recorded in Arrian's Ektaxis. In 162, it fought against the Parthians again, and again captured the capital of Artaxata. In 172, it fought under Marcus Aurelius against the Quadi. In the 3rd century, the Legion took part in numerous expeditions, and was stationed for many years at Melitene. It was a region where Christianity became popular very early, which is why this Legion can be found in martyrologies. Its emblem was a thunderbolt.