The original trade routes for the products of India were overland. The goods were borne in caravans from the North-West frontier of India across Persia to Aleppo and thence by ship to Italy and to whatever other country was rich enough to purchase them. But after the growth of Muhammadanism and of the power of the Turks, the caravan routes across Central Asia became unsafe. Two new routes then came into use, the one by the Persian Gulf, and the other by the Red Sea. Goods which went by the Persian Gulf were carried overland to Aleppo and other ports in the Levant; goods that went by the Red Sea were carried across Egypt from Suez to Alexandria. From these two entrepôts of Eastern and especially of Indian trade the articles of commerce were fetched by Venetian ships, and from Venice were distributed throughout Europe. In the days of the Renaissance the products of the East passed through the hands of Muhammadan merchants from India to the Mediterranean, and the large profits they made were commensurate with the risks they undertook. With the rapid growth of civilisation the value of this trade became enormous: every city through which it passed was enriched; Venice became the wealthiest State in Europe; and the cost {21} of all Indian luxuries and spices was extravagantly high. All wise kings envied the prosperity of Venice, and schemed to secure a share of the Eastern trade for their subjects. Mention has been made of the five illustrious princes, the sons of John the Great and Eleanor of Lancaster. One of them is known in history as Prince Henry the Navigator. This prince devoted his life to the discovery of a direct sea route from Portugal to India. He established himself on the promontory of Sines, and collected around him the most learned geographers and mathematicians of the age. With them he discussed the probability of its being possible to sail round the continent of Africa and thus reach India. Year after year he sent forth expeditions to explore the African coast. Many and important discoveries were made by his navigators, and a generation of skilful pilots and adventurous sailors was formed by his wise encouragement. Among the earliest discoveries by the sailors of Prince Henry were the islands of Madeira and the Azores, and at the time of his death, in 1460, the Portuguese navigators had learned the way past the River Senegal. What Prince Henry the Navigator began was continued by the enterprise of the Portuguese merchants. These men were not actuated by the high aims of Prince Henry; they were rather inclined to mock at his belief in the existence of a direct sea route to India. But with his discoveries along the African coast began the slave trade. It was found {22} to be excessively profitable to import negroes from the Guinea coast, and the Portuguese captains and pilots soon mastered the difficulties of the navigation of the North-West shoulder of Africa from the frequent voyages which they made in search of slaves.