In 88 BC, after being sidelined by his political opponents, Sulla marched his legions on Rome and took the capital. He took revenge on his enemies and forced Marius into exile, Sulla then left Italy to fight the First Mithridatic War against Mithridates VI of Pontus. After Sulla left, violence erupted between the optimates, led by the consul Gnaeus Octavius, and the populares, led by the consul Lucius Cornelius Cinna. Sertorius, being a former subordinate of Marius, declared for Cinna and the populares. When Cinna was driven from Rome he and Sertorius started recruiting ex-legionaries and drumming up enough support to enable them, in their turn, to march on Rome. Though he had a very bad opinion of Marius by then, he consented to Marius's return upon understanding that Marius came at Cinna's request and not of his own accord.