A breakthrough study published by the International Institute for Silk Road Studies has identified a previously unknown luxury trade network dubbed the 'Naphtha Route'. By using isotopic analysis on 6th-century ceramic lamps found in Sasanian-era ruins, researchers discovered that raw petroleum from the Baku peninsula was traded as far as the Indus Valley and Byzantium for use in ritual fires and advanced military incendiaries.
The discovery of specialized amphorae designed to transport liquid bitumen suggests that the Silk Road was far more than a textile exchange; it was a complex network for industrial energy resources. This research redraws the economic map of the late antique world, highlighting the Caspian Sea as a critical hub for maritime trade between the East and West.