The Fimbrian or Valerian legions were two Roman legions which served and fought in all three wars against King Mithridates of Pontus, one of the Roman Republic's chief adversaries during the 80s, 70s and 60s BC. They became a body of long serving legionaries known for their fierce fighting reputation and also, more infamously, for mutiny and abandoning their commander. The legions take their name from the consul Lucius Valerius Flaccus, who first recruited them in 86 BC, and from his subordinate, Gaius Flavius Fimbria, who took command of the legions after inciting a mutiny and murdering Flaccus.
Formation and first mutiny
In 86 BC, the populares, in control of the Roman government, dispatched suffect consul Lucius Valerius Flaccus with an army to the province of Asia as a political countermeasure to Lucius Cornelius Sulla, their main opponent. Sulla was campaigning in Greece and Macedon fighting against the forces of king Mithridates of Pontus (see: First Mithridatic War). Flaccus probably employed experienced troops, drawing his recruits from veterans of the recent Social War, but due to a lack of funds he was only able to raise two legions. In 86 or 85 BC, Flaccus took his legions through Northern-Macedonia and Thrace to the Hellespont (to cross over into Asia Minor). Flaccus was unpopular with his troops and by the time they had reached the Bosporus, Gaius Flavius Fimbria, one of his legates (lieutenants), taking advantage of Flaccus’s absence, incited a mutiny. Flaccus returned to his army, failed to put down the mutiny, tried to flee, but was hunted down and executed. Fimbria cut off his head and hurled it into the sea. The Valerians now became the Fimbrians.
The First Mithridatic War
Following the mutiny, Fimbria and his men decided to continue their journey in the hopes of defeating Mithridates and redeeming their treasonous behavior [the mutiny] in the eyes of the Roman government. Arriving in Asia Minor, the Fimbrians plundered their way towards Pergamum, Mithridates's Asian capital. When Mithridates sent an army to protect the city, Fimbria managed to take the Pontic forces by surprise and annihilated them. With the relief army destroyed, he then laid siege to Pergamum. Upon learning of the defeat, Mithridates decided to head for Pontus in order to raise another army.
As Mithridates awaited his fleet at Pitane on the northwestern coast of Asia Minor, the Fimbrians surprised him again, appearing at the gates of Pitane and besieging the town. Soon after a Roman fleet arrived under the command of Lucius Licinius Lucullus, a legate of Sulla. Although this fleet could have completed the encirclement and prevented Mithridates from escaping Pitane, Sulla—the chief political opponent of Fimbria's faction in Rome—had signed a separate armistice with Mithridates and Lucullus did not interfere when the Pontic fleet arrived to evacuate the king.
Mutiny against Fimbria
After failing to capture Mithridates, Fimbria allowed his troops to pillage several cities, most prominently razing Ilium to the ground. Unfortunately for Fimbria, Sulla and his much larger army eventually approached and laid siege to Fimbria's camp. At this point Fimbria's men turned on him, once again deserting their commander. After a failed attempt at arranging Sulla's assassination, Fimbria committed suicide. When Sulla left Asia Minor to fight another civil war in Italy, he left the Fimbrians in Asia Minor to guard the Roman provinces.
The Second Mithridatic War
In 83 BC one of Mithridates' generals, Archelaus, defected to the Romans. Archelaus convinced Lucius Licinius Murena, the Roman general tasked with protecting Bithynia, that Mithridates was planning another war with Rome. Murena marched his army, including the Fimbrians, across the river Halys into Pontic territory. This operation was less an invasion than a large-scale raid for plunder. The next year Murena repeated his actions, looting as many as 400 villages before Mithridates counterattacked. The Pontic king defeated the Roman force and drove Murena back to Bithynia. Subsequently, Aulus Gabinius, a representative of Sulla, arrived from Rome with instructions to cease all hostilities. This concluded the Second Mithridatic War.