Following the fall of southern Ravenna in 902, the League of Napoli was recognized as a force to be reckoned with in Italy. Multiple battles with the Carolingians prevented them from gaining much territory following the fall of Ravenna, though it also prevented the Carolingians from taking territory from the League of Napoli. The Emirate of Sicily, at war with the Carolingians over Carolingian Sicily, offered an alliance to the League of Napoli. With Sicily on the League's side, the League was able to invade Spoleto.
The League of Napoli invaded the city state of Spoleto in 908 from the south while the Emirate of Sicily distracted the Carolingian Eastern Fleets with several naval battles in the Adriatic Sea and the Ionian Sea. Before long, the city of Spoleto was reached by the League of Napoli. While the Carolingian occupiers attempted to fight back against the League of Napoli, the League sieged the city of Spoleto for several months. In February of 909, the siege broke and the Napolitan forces entered Spoleto.
The initial battle went well, despite the league heavily damaging the crucial Ponte Sanguinario in their final push into the city. Before long, the Napolitans had trapped the Carolingians in the city, flanking it on all sides before finally taking out the remaining Carolingian holdings in the northern flank of the city.
The Second Battle of Spoleto led to the creation of the second Duchy of Spoleto. Led by military ruler Landulf I for a short time, Spoleto became an important location for the League of Napoli until the Sicilian Emirate's betrayal in 920. Furthermore, the victory at Spoleto rallied the Napolitans to continue pushing the Carolingians out of Italy. The battle did have consequences on Spoleto's landmarks, including the Ponte Sanguinario, which had collapsed before the Carolingian reclamation of the city in the later stages of the Italian Wars.