In 1453, while this exchange was at its height, the Turks conquered Constantinople, seized the caravan routes, and ruined the trade. Gold and pearls, ivory and diamonds, spices and silks, could no longer be secured unless a waterway could be found to the East. Prince Henry the Navigator, a Portuguese, though many of his captains thought that in the torrid zone the ocean was boiling and that flames filled the air, succeeded in reaching almost to the equator before his death in 1460. In 1487, Diaz continued the work to the Cape of Good Hope. Christopher Columbus, believing the earth a sphere, thought that by sailing due westward only two thousand five hundred miles he would reach China and India. So in August, 1492, after seeking aid in vain from Portugal, England, and his own country, he braved the "Sea of Darkness" in a Spanish ship. Though some Portuguese sailors had said, "You might as well expect to find land in the sky as in that waste of waters," in October of the same year he made the discovery that gave to the world a new continent. Then the spirit of adventure and aggrandizement dominated the Spanish race. Ponce de León, Fernando Cortez, Pizarro, and Fernando de Soto continued the work until June, 1543. Luis de Moscoso, the successor of de Soto, with a remnant of his once proud force, now reduced to about three hundred men, in boats descended the Mississippi River to its mouth; from the boats they were the first white men to behold the land that is now Kentucky. England, so far, had been very quiet and conservative about discovering, exploring, or settling. Finally, English fishermen came to Newfoundland. Sir John Hawkins traded negroes for hides and pearls, and Sir Francis Drake ravaged the Caribbean coast and in 1577-1580 sailed around the world. Soon Sir Humphrey Gilbert attempted colonization, which was taken up by his half brother, Sir Walter Raleigh, who sent two ships under Philip Amadas and Arthur Barlowe, who discovered the coast of North Carolina. Upon their return, Queen Elizabeth named it Virginia. Kentucky was included in the charter of this first colony, which was settled at Jamestown, 1607.