In the seventeenth century, Europeans on the Gold Coast took gold pawns as security for debt, but from the early eighteenth century, they turned increasingly toward the use of human pawns. This shift was the result of a transformation in levels of demand for gold amongst African sellers, most notably the Asante, who began to secure control over local gold sources from c. 1700. The change in demand for gold was accompanied by a rise in slave prices on the West African coast, but it was the indigenous system of debt recovery that proved crucial to the success of European trade.