The Sertorian War was a civil war in the Roman Republic fought from 80 to 72 BC between two Roman factions, one led by Quintus Sertorius and another led by the senate as constituted in the aftermath of Sulla's civil war. The war was fought on the Iberian Peninsula (called Hispania by the Romans) and was one of the Roman civil wars of the first century BC. The Sertorians comprised many Roman exiles from the Sullan proscriptions led by Sertorius, who fashioned himself proconsul, and native Celts, Aquitanians, and Iberians.
The war takes its name from Quintus Sertorius, the leader of the opposition. It was notable for Sertorius' successful use of guerrilla warfare. Sertorius was sent by the Marian regime as proconsul to Hispania in 83 BC, but was ejected by a Sullan army in 81 BC. He returned in 80 BC, landing in Hispania Ulterior, and campaigned with success against the Sullan governors, depicting himself as the legitimate Roman governor of Hispania while winning over the native tribes.