 "Clavenna" belonged to the Italian territories retaken by the Byzantine Empire in the mid-6th century during the reign of Emperor Justinian the Great and avoided capture by the Lombard kingdom until the 7th century.Clavenna probably derived some importance from its position at the junction of the two pass roads, as does the modern town of Chiavenna, which is the chief town of the surrounding district.When the East Frankish king Otto I married the dowager queen Adelaide of Italy in October 951 and campaigned against King Berengar II, he assigned the Val Bregaglia and the control over Septimer Pass to the Bishopric of Chur, while the Bishops of Como held the adjacent estates from Villa down to Chiavenna in the southwest (corresponding to the current Italian-Swiss border).