The Duchy of the Southern Marches is a duchy controlling the western Border between the Kingdom of the Isles and Kesh. It compromises of Land's End (barony) ,Landreth (Earldom), and later Port Vykor. The title carried with it is Lord Sutherland. Following the Serpentwar, Duko was announced the Duke after the death of Lord Sutherland and the Earl of Landreth.