Vaison-la-Romaine grew from Vasio, the principal settlement of the Vocontii in the upper Ouvèze valley. The Vocontii were a Gallic people who entered Rome’s sphere before the full conquest of Gaul and retained a degree of local organization under imperial rule. Vasio occupied fertile ground near routes between the Rhône corridor and the Alpine interior. Unlike many Roman colonies imposed after conquest, its development reflects the gradual transformation of an existing regional center whose elite adopted Latin institutions, monumental architecture, and Mediterranean patterns of consumption.

During the first and second centuries CE, Vasio became one of the wealthiest towns in Roman Provence. Streets, drains, shops, baths, fountains, and porticoes organized the lower settlement. Large residences such as the House of the Dolphin and the House of the Laurelled Apollo combined reception rooms, gardens, service spaces, and mosaic decoration. On the Puymin hill, a theater seating several thousand spectators hosted drama and civic gatherings. These amenities depended on skilled builders, water management, trade, taxation, and the agricultural production of the surrounding territory.

The town’s inhabitants included local landowners, merchants, craftspeople, laborers, enslaved people, officials, and immigrants from elsewhere in the empire. Inscriptions reveal civic benefaction and family ambition, but they preserve only part of the population’s experience. Christianity became established in late antiquity, and Vaison developed as an episcopal center. Political insecurity and changing settlement patterns encouraged residents to occupy the more defensible rocky height across the Ouvèze, where the medieval upper town and castle later took shape, while the extensive Roman neighborhoods were gradually buried.

Ancient masonry never vanished entirely. The Roman bridge continued to carry traffic across the river, an exceptional survival that demonstrated the durability of imperial engineering. Archaeological discoveries in the nineteenth and twentieth centuries exposed the districts of Puymin and La Villasse. Canon Joseph Sautel led major excavations from 1907 onward and helped establish the museum that now bears the name of his collaborator and patron Théo Desplans. Excavation revealed houses and streets but also required choices about reconstruction, presentation, and the removal or protection of finds.

The two archaeological parks now cover more than eight hectares, preserving residences, commercial areas, baths, and the restored theater. The bridge remains part of the living town, while artifacts from the excavations are displayed in the museum. Modern Vaison therefore spreads across ancient, medieval, and contemporary centers rather than replacing one with another. Its remains illuminate how a Gallic community prospered through Roman civic life, how domestic luxury rested on wider labor and exchange, and how archaeology reintroduced a buried city into the identity of modern Provence.