The Romans who colonized the city in 241 BC constructed this small theater in the 1st century AD; for centuries afterward it was used as a quarry for building materials. The most intact portion is the hallway that passes under the cavea (stands). The rest was heavily restored in the early 1950s and serves as a venue for Spoleto's Festival dei Due Mondi. The theater was the site of a gruesome episode in Spoleto's history: during the medieval struggle between Guelph (papal) and Ghibelline (imperial) forces, Spoleto took the side of the Holy Roman Emperor. Afterward, 400 Guelph supporters were massacred in the theater, their bodies burned in an enormous pyre. In the end, the Guelphs were triumphant, and Spoleto was incorporated into the states of the Church in 1354. Through a door in the west portico of the adjoining building is the Museo Archeologico, with assorted artifacts found in excavations primarily around Spoleto and Norcia. The collection contains Bronze Age and Iron
Age artifacts from Umbrian and pre-Roman eras. Another section contains black-glaze vases from the Hellenistic period excavated from the necropolis of Saint Scolastica in Norcia. The highlight is the stone tablet inscribed on both sides with the Lex Spoletina (Spoleto Law). Dating from 315 BC, this legal document prohibited the desecration of the woods on the slopes of nearby Monteluco.