The Chinese had invented the compass in the eleventh century, and had excellent boats. Before his death in 1433, Zheng He, a Chinese Muslim, had explored the coast of much of Asia and eastern Africa, leading two hundred ships and twenty-seven thousand sailors. But China was the richest country in the world, and by the late fifteenth century no longer allowed travel beyond the Indian Ocean, on the theory that the rest of the world was unworthy and uninteresting.
