during these centuries, while religious feeling revived, and enormous exertions were made to Christianize the heathen. In fact, Christianity was widely spread by the end of the twelfth and thirteenth centuries, while a bitter war was being waged against the Saracens, who dominated Africa and the Mediterranean, keeping Genoa and Venice in check, while their armies conquered Spain, and even invaded France. But the energies of these intrepid warriors were not confined to war alone, for they sought for commerce, and there is little doubt but that they were acquainted with the Red Sea, with the east coast of Africa as far as Madagascar, and with much of the west coast of the same continent. But their knowledge was obtained for the most part not by voyages, but by overland routes, so that the interior, perhaps, rather than the coast-line was known. In course of time these Saracens were beaten back by the tide of Christian chivalry, and then we find the Genoese prospecting voyages, in which they explored the Atlantic border of Africa, and wondered whether a passage existed to the due west by means of which they could reach India, the Far East. And now we come to that period, extending over some sixty years, during which the Portuguese sent expeditions south along the west coast of Africa. These voyages, at first productive of only a few slaves, and later of a huge traffic in these unhappy victims of their raids, finally ended in the wonderful achievement of Bartolomeo Diaz, who rounded the Cape of Good Hope in 1485. Ten years later the intrepid Vasco de Gama doubled this cape, and sailed along the eastern coast of Africa to Durban, and from there to India itself, thus proving the existence of the huge continent of Africa, and the possibility of a passage to the Far East by way of the Cape of Good Hope. However, this was not that due westerly route which philosophers and wise men spoke of, which tradition almost laid down as a fact, and the adventurous nations still pondered, still wondered whether it existed. Even in England the subject was as much in the minds of our sailors as in those of Portugal and Spain, and many a ship put out from Bristol intent on its discovery. But the attempt always ended in failure, for, after steering to the west for two weeks, perhaps, the mariners would fancy that they were on the wrong track, and would make some other course, finally returning disappointed to Bristol.