The place name refers to a 3rd-century AD Roman fortified settlement built during the reign of Emperor Aurelian, reinforced by the Byzantines in the 6th century. The first parish, San Michele, is probably dating back to the 10th century. Between the 12th and 13th century various families led the administration of Campo, until the year 1329, when it becomes a small fief within the Holy Roman Empire, surrounded by the territory of the Republic of Genoa.