In 1487, King John II of Portugal dispatched Bartolomeu Dias to find the sea route round Africa and into the Indian Ocean. But King John didn’t just send ships: he sent spies too. In particular, Pêro da Covilhã, a low-born but multilingual adventurer. Covilhã, with letters of exchange to pay his way, made his way to Alexandria, the entry port to the Islamic world and then, passing himself off as a Muslim merchant, he made his way to Cairo and then on to Aden where he took ship on a dhow across the Indian Ocean, arriving in Calicut, India. Taking notes on the Indian Ocean spice trade, Covilhã then returned to Cairo where he met emissaries sent by John II, giving them his report. Now apparently bit by wonderlust, Covilhã explored Arabia, even entering Mecca and Medina in disguise as a Muslim pilgrim, before venturing across the Red Sea to Mount Sinai. From there, the indefatigable Covilhã headed to Ethiopia, the Christian kingdom in the heart of Africa and the probable source of the legends of Prester John. The ruler, Eskender, received Covilhã well but refused to let him leave. Thirty years later, a Portuguese embassy met their countryman, still living in the court of the kings of Ethiopia.