The battle and siege of Spoletium (82 BC) was a partial success for Pompey, then serving under Sulla, against Carrinas, one of the lieutenants of the consul Carbo (Sulla's Second Civil War).
At the start of the campaign of 82 BC, Sulla split his forces, sending Metellus Pius and Pompey to occupy Cisalpine Gaul, while Sulla himself advanced towards Rome from Campania. The two consuls for the year also split up, with the younger Marius heading south to face Sulla, while Gnaeus Papirius Carbo moved north to face Metellus.
Carbo's campaign began with a defeat, when Metellus defeated his lieutenant C. Carinas on the River Aesis, the northern boundary of Picenum, on the Adriatic Coast. Carbo then came up in person, and besieged Metellus somewhere to the north of Ariminum (Rimini). In the meantime Marius suffered a heavy defeat at Sacriportus, and was forced to retreat to Praeneste, where he would be besieged for the rest of the war. The news of this defeat forced Carbo to abandon the siege, and retreat back towards Ariminum, with Pompey on his heals.
Carbo continued to retreat south, heading back towards Rome, but Sulla beat him to the city, and Carbo ended up Spoletium, about 80 miles to the north of Rome. Carbo appears to have split his army as it moved south, with his wing on the Via Cassia, and another detachment, under Carrinas, on the Via Flaminia. Carrinas moved towards Spoletium (Spoleto), 40 miles to the east/ south-east of Carbo at Clusium.
Pompey had continued to follow Carbo south, and along the way he had joined up with Crassus (an early association of the future triumvirs). They caught up with Carinnas in the plain of Spoletium, presumably the flat valley to the north of the city. In the resulting battle they killed 3,000 of Carinnas's men. He escaped, but was forced to take refuge in Spoletium, where he was besieged.
This came at about the same time as the first battle of Clusium, a hard fought but inconclusive day long battle between Sulla and Carbo. In the aftermath of the battle the two commanders stayed in the same general area. Carbo sent reinforcements east to try and help Carinnas, but Sulla sent troops to ambush them, winning a victory in which another 2,000 of Carbo's men were killed.
Pompey was unable to take full advantage of Sulla's aid. Carinnas managed to escape from Spoletium at night, under the cover of a heavy rain storm, and rejoined Carbo's army.
Carbo's efforts continued to end in failure. He sent Marcius, with eight legions, to try and lift the siege of Praeneste, but they were ambushed by Pompey while passing through a defile and most of Marcius's army was either killed or deserted - one entire legion marched off to Ariminum (Rimini), which was at least still in Marian hands, but most of the rest of the army dissolved, leaving Marcius with only seven cohorts when he returned to Carbo. Carbo then attempted a surprise attack on the camp of Metellus Pius (Sulla's commander in the north) at Faventia, but this ended in disaster. Soon after this Cisalpine Gaul, one of the main centres of support for the Marian cause, changed sides, and a discouraged Carbo decided to flee into exile in Africa in the hope that he could raise a fresh army there.