Aceh's influence on Perak began to wane when the Dutch East India Company (VOC) arrived, in the mid–17th century. When Perak refused to enter into a contract with the VOC as its northern neighbours had done, a blockade of the Perak River halted the tin trade, causing suffering among Aceh's merchants. In 1650, Aceh's Sultana Taj ul-Alam ordered Perak to sign an agreement with the VOC, on condition that the tin trade would be conducted exclusively with Aceh's merchants. By the following year, 1651, the VOC had secured a monopoly over the tin trade, setting up a store in Perak. Following long competition between Aceh and the VOC over Perak's tin trade, on 15 December 1653, the two parties jointly signed a treaty with Perak granting the Dutch exclusive rights to tin extracted from mines located in the state.