Portugal freed her territory of the Mohammedan Moors nearly a century earlier than Spain; and the vigor and intelligence of a great king, John I., brought Portugal, about the year 1400, to an important place among the states of Europe. This king captured from the Moors the city of Ceuta, in Morocco; and this was the beginning of modern European colonial possessions, and the first bit of land outside of Europe to be held by a European power since the times of the Crusades. King John's youngest son was Prince Henry, famous in history under the title of "the Navigator." This young prince, with something of the same adventurous spirit that filled the Crusaders, was ardent to extend the power of his father's kingdom and to widen the sway of the religion which he devotedly professed. The power of the Mohammedans in the Mediterranean was too great for him hopefully to oppose and so he planned the conquest of the west coast of Africa, and its conversion to Christianity. With these ends in view, he established at Point Sagres, on the southwestern coast of Portugal, a naval academy and observatory. Here he brought together skilled navigators, charts, and geographies, and all scientific knowledge that would assist in his undertaking. [3] He began to construct ships larger and better than any in use. To us they would doubtless seem very clumsy and small, but this was the beginning of ocean ship-building. The compass and the astrolabe, or sextant, the little instrument with which, by calculating the height of the sun above the horizon, we can tell distance from the equator, were just coming into use. These, as well as every other practicable device for navigation known at that time, were supplied to these ships. Exploration of the African Coast.--Thus equipped and ably manned, the little fleets began the exploration of the African coast, cautiously feeling their way southward and ever returning with reports of progress made. Year after year this work went on. In 1419 the Madeira Islands were rediscovered and colonized by Portuguese settlers. The growing of sugarcane was begun, and vines were brought from Burgundy and planted there. The wine of the Madeiras has been famous to this day. Then were discovered the Canaries and in 1444 the Azores. The southward exploration of the coast of the mainland steadily continued until in 1445 the Portuguese reached the mouth of the Senegal River. Up to this point the African shore had not yielded much of interest to the Portuguese explorer or trader. Below Morocco the great Sahara Desert reaches to the sea and renders barren the coast for hundreds of miles.