After signing the peace treaty at Dardanos, Sulla returned to Rome with the intention of confronting his other political opponents, the Populares. They were led by Gaius Marius the Younger and by Gnaeus Papirius Carbo. Sulla therefore invaded Italia in 83 BC, routing various Populares armies. Encamping for the winter, both sides made preparations to continue the fighting with the start of the Spring war season when the war became intensified and bloody.
According to historical accounts, one night in April, Sulla had a dream that Gaius Marius told his son, Gaius Marius the Younger, that he should not give battle to Sulla's forces the following day. Encouraged by this premonition, Sulla decided to immediately give combat and called on Gnaeus Cornelius Dolabella who was encamped nearby. Dolabella's army was exhausted from marching in an intense rainstorm and the military tribunes had ordered that the army make camp rather than give battle. Emboldened by the enemy's lack of offensive action, Gaius Marius decided to attack thinking he would be able to surprise the Optimates and win the day. The Optimates instead rallied to their units and gave battle against troops of Marius. Their defense was so fierce that Marius was eventually obliged to retire from the fray.
The surviving Populares forces, including Marius, took refuge at Preneste to escape the pursuing Sullan forces. Sulla arrived shortly thereafter and besieged the city. The city fell on 4 November, holding out surprisingly until all of Italy was under Sulla's direct control.