In 1418, Portuguese explorers under the patronage of Prince Henry the Navigator discovered the Madeira Islands approximately 450 miles off the west coast of modern-day Morocco. Soon after, Portugal commenced the colonization of the uninhabited islands of Madeira and Porto Santo. The earliest settlers included mariners, merchants, missionaries, craftsmen, artisans, freemen, and convicts from Portugal. Slaves, captured in Morocco, Mauritania (south of Morocco), the Canary Islands, and the Guinea coast of West Africa worked the lands and crops of the coastal estates of the Madeiran nobility.