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 was killed at Munda.
He most likely had early ties with Pompey during his time as a patron for Picenum and his desire to rise in military rank.
[1] His early service was c. 78–75 BC in Cilicia under Publius Servilius Vatia Isauricus fighting pirates and the Isaurian hill tribes.
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.
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.
That indirectly secured for Caesar the dignity of pontifex Maximus, by his act of supporting Labienus in this cause (Dio Cassius xxxvii.
[4] Labienus was more a soldier than politician and primarily used his office as a gateway to secure himself positions of high military command.
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.
[10] 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.
From the defeat at the Battle of Pharsalus, where he commanded the cavalry, he fled to Corcyra, and after hearing of the death of Pompey then proceeded to Africa.
[4] He created confidence in the followers of Pompey by lying to them, claiming that Caesar had received a mortal wound at the Battle of Pharsalus.
[4] Death came to Labienus in the Battle of Munda, an evenly matched conflict between the armies of Caesar and the sons of Pompey.
According to Appian, (BC2.105), his head was brought to Caesar, who then dispatched men to locate the body of his old friend, and buried him with full honours.