The river Daugava has been a trade route since antiquity, part of the Vikings' Dvina-Dnieper navigation route to Byzantium. A sheltered natural harbour  upriver from the mouth of the Daugava — the site of today's Riga — has been recorded, as ''Duna Urbs'', as early as the 2nd century. It was settled by the Livs, an ancient Finnic tribe.