According to the Treaty of Zohab (May 1639), following the end of a period of conflict between the Ottoman and Persian Empires, the frontier between them was not a line but a broad zone running through Armenia, Azerbaijan, the Western Zagros Mountains and as far south as Basra and the Persian Gulf. Isolated from distant capitals and inhabited by hostile Arab and Kurdish tribes jockeying for patronage from the rival empires, these border areas were extremely unsettled. Both empires fought over the revenues of the local tribes and repeatedly raided each other across the border. It was upon this volatile and unsatisfactory backdrop that a cooling of relations between the two empires at the end of the Napoleonic Wars provoked a bloody and damaging conflict that ultimately settled nothing.