For centuries European trade with India and Cathay (China) had been conducted along the various tributaries of the Silk Road. Eastern products such as precious metals and gem stones, perfumes, spices and fine textiles were highly prized in Europe, but were subject to high transport costs and, once the Ottomans took control of Constantinople in 1453, militant political and financial interference. However, the Venetians managed to maintain the trade in eastern goods through Constantinople and the Levantine ports, and charged exorbitant prices to their customers in Western Europe. The Portuguese explorer Vasco da Gama finally made direct contact with the Indies in 1498 via the Cape of Good Hope in southern Africa. For nearly a century the Portuguese retained a trading monopoly on this seaborne route to the East Indies, Arabia and the east coast of Africa. They also planted the Roman Catholic Christian religion in much of the region. One problem was that most eastern countries had little interest in European products and would only take payment in silver or gold and possibly slaves from Africa. Much of the supply of silver from mines in Spanish-America finished in the hands of Portugal’s eastern trading partners. Later in the early 17th century, trade was in decline, Portugal was beginning to lose naval superiority and Dutch and English traders were also beginning to prospect for business in the region. The Mughal Empire in India reached the height of its power at that time.