The Social War (from Latin bellum sociale, "war of the allies"), also called the Italian War or the Marsic War, was fought largely from 91 to 88 BC between the Roman Republic and several of its autonomous allies (socii) in Italy. Some of the allies held out until 87 BC.
The war started in late 91 BC, with the rebellion of Asculum. Other Italian towns quickly declared for the rebels and the Roman response was initially confused. By the new year, the Romans had levied huge armies to crush the rebels but found initial headway difficult. By the end of the year, however, they were able to cut the Italian rebels into two, isolating them into northern and southern sectors. The Italian rebels attempted to invade Etruria and Umbria at the start of 89 BC but were defeated. In the south, they were defeated by Lucius Cornelius Sulla, who for his victories would win a consulship the next year. The Romans retained the initiative and by 88 BC, the conflict was largely over and Roman attention had been captured by the ongoing First Mithridatic War. The few Italian rebels on the field by 87 BC eventually reached a negotiated settlement during a short civil war that year. At various stages of the war, Romans brought legislation allowing Italian towns to elect Roman citizenship if they had not revolted or would otherwise put down arms, draining support from the rebels.