The Portuguese position on the Gold Coast, known as Portuguese Gold Coast, remained secure for over a century. During that time, Lisbon sought to monopolize all trade in the region in royal hands, though appointed officials at São Jorge, and used force to prevent English, French and Dutch efforts to trade on the coast. After Barent Eriksz successfully sailed to the Gold Coast in 1591, Dutch merchants began trading in the area. Pieter de Marees's publications greatly increased the interest of merchants in the region.