République ligurienne
Initially it comprised the former Piedmontese provinces of Alessandria, Casale, Tortona, Voghera and Bobbio. Following the annexation of the Ligurian Republic to France in 1805, Voghera, Bobbio and Tortona passed to the newly created Department of Genoa, while the Department of Marengo acquired Asti, previously in the Department of Tanaro.