Henry wished to know how far Muslim territories in Africa extended, hoping to bypass them and trade directly with West Africa by sea, find allies in legendary Christian lands to the south like the long-lost Christian kingdom of Prester John and to probe whether it was possible to reach the Indies by sea, the source of the lucrative spice trade. He invested in sponsoring voyages down the coast of Mauritania, gathering a group of merchants, shipowners and stakeholders interested in new sea lanes. Soon the Atlantic islands of Madeira (1419) and the Azores (1427) were reached. In particular, they were discovered by voyages launched by the command of Prince Henry the Navigator. The expedition leader himself, who established settlements on the island of Madeira, was Portuguese explorer João Gonçalves Zarco.