Titus Labienus (c. 100 BC – 17 March 45 BC) was a high-ranking military officer in the late Roman Republic. He served as tribune of the Plebs in 63 BC. Although mostly remembered as one of Julius Caesar's best lieutenants in Gaul and mentioned frequently in the accounts of his military campaigns, Labienus chose to oppose him during the Civil War, and he was killed at Munda. He was the father of Quintus Labienus.
As his praetorship was in 60 or 59 BC, Titus Labienus most likely was born around 100 BC. Many sources suggest that he came from the town of Cingulum in Picenum. His family was of equestrian status. He most likely had early ties with Pompey during his time as a patron for Picenum, also because of his desire to rise in military ranks. His early service was c. 78–75 BC in Cilicia under Publius Servilius Vatia Isauricus fighting pirates and the Isaurian hill tribes.
Tribune of the Plebs, Trial of Gaius Rabirius
In 63 BC, Titus Labienus was a tribune of the Plebs with close ties to Pompey. Gaius Julius Caesar was also working closely with Pompey and therefore he and Labienus occasionally cooperated, developing into a friendship between both men.
At Caesar's instigation, Labienus accused Gaius Rabirius of high treason (perduellio) for the murder of the tribune Lucius Appuleius Saturninus and of his uncle Titus Labienus in 100 BC. The purpose of this trial was to discredit the so-called "final decree of the Senate" (senatus consultum ultimum), an emergency measure of the senate commonly used against the Populares and the Roman assemblies. Labienus used the antiquated procedure of the duumviri, used in the early republic, against Rabirius. The procedure bypassed normal criminal law and Rabirius would be tried without defense. Since tribunes were sacrosanct, it was seen as an act against the gods to kill one. Thus punishment of the culprit was seen as more of a cleansing to appease the gods. The killing was seen as a pollution so profound that a normal criminal trial was unnecessary and immediate cleansing was necessary to avoid the wrath of the gods. The duumviri were assigned to accuse under the pretense of obvious guilt and cleanse the culprit through scourging.
Rabirius appealed to the Centuriate Assembly and Cicero spoke in his defense. However, before the assembly could vote, Metellus Celer used his powers as an augur to claim the sightings of bad omens and take down the flag in Janiculum, sabotaging the process and forcing a re-trial. Rabirius was ultimately sentenced to exile, as he was unable to pay an unreasonable fine.
Most significantly, in the same year, Labienus carried a plebiscite returning the elections of the pontifices to the people. Caesar then ultimately swept the subsequent election for Pontifex maximus when it came time to replace deceased Metellus Pius (Dio Cassius xxxvii. 37).
Labienus then had to serve as praetor in either 60 or 59 BC, as he was appointed Caesar's legatus pro praetore in Cisalpine Gaul through Lex Vatinia.
Labienus was more a soldier than politician and primarily used his office as a gateway to secure himself positions of high military command.
Lieutenant under Caesar in Gaul
As Caesar's senior legate during his campaign in Gaul, Labienus was the only legate mentioned by name in Caesar's writings about his first campaign. He was a skilled cavalry commander.
Labienus commanded the winter quarters in Vesontio in 58 BC. He also had full command of the legions in Gaul during Caesar's absence, as his legatus pro praetore. He had this privilege when Caesar was administering justice in Cisalpine Gaul as well as during Caesar's second campaign in Britain (in 54 BC).
In 57 BC, during the Belgian campaign, in a battle against the Atrebates and Nervii near Sabis, Labienus, commanding the 9th and 10th legions, defeated the opposing Atrebates force and proceeded to take the enemy camp. From there he sent the 10th Legion against the rear of the Nervii line while they were engaged with the rest of Caesar's army, single-handedly turning the tide of battle and securing Caesar the victory.
Labienus is also credited with the defeat of the Treviri under Indutiomarus. Labienus spent days with his army fortified in their camp, while Indutiomarus harassed him daily in an attempt at intimidation and demoralization. Labienus waited for the right moment, when Indutiomarus and his forces were returning to their camp disorganized, to send out his cavalry through two gates. He gave them the orders to first kill Indutiomarus, then his trailing forces on their return. Labienus's men were successful, and with the death of their leader, the Treviri army scattered. The Treviri forces later regrouped under relatives of Indutiomarus and moved upon Labienus, setting up camp across the river from his legions, waiting for reinforcements from the Germans. Labienus feigned a withdrawal, enticing the Treviri to cross the river, after which he turned around and had his men attack. Being in such a disadvantageous position, the Treviri forces were shattered. After hearing this, the German reinforcements turned around.
Labienus's victory over the Parisii commanded by Camulogene at Lutetia in the Battle of Lutetia is another example of his tactical genius. Sending five cohorts back towards Agedincum, and himself crossing the Sequana River with three legions, he tricked the enemy into thinking that he had divided his army and was crossing the river in three places. The enemy army split into thirds and pursued Labienus. The main body met Labienus which he subsequently surrounded with the rest of his legions. He then annihilated the reinforcements with his cavalry.
In September, 51 BC, Caesar made Labienus governor of Cisalpine Gaul.
Defection from Caesar, command under Pompey in Civil War
After Caesar crossed the Rubicon, Labienus left his post in Cisalpine Gaul and joined Pompey. He was rapturously welcomed on the Pompeian side, bringing some Gallic and German cavalry with him. He also brought an account on Caesar's military strength.