Mainly living on the right bank of the Ouvèze river in Roman times and until the 12th century, the inhabitants of what is now Vaison-la-Romaine migrated during the troubled times of the Middle Ages. They settled on the steep rock on the left bank of the river, sheltered by the ramparts and the feudal castle built by the Counts of Toulouse, which later became a papal property. This is where the medieval city, whose cobbled streets are still visible today, developed.