In 1415, Ceuta was conquered by the Portuguese with the aim of controlling navigation of the African coast, expanding Christianity with the avail of the papacy, and providing the nobility with war. The king's son, Henry the Navigator, then became aware of the profitability of the Saharan trade routes. Governor of the rich 'Order of Christ' and holding valuable monopolies on resources in the Algarve, he sponsored voyages down the coast of Mauritania, gathering a group of merchants, shipowners, and stakeholders interested in the sea lanes. Later, his brother Prince Pedro granted him a "Royal Flush" of all profits from trading within the discovered areas. Soon the Atlantic islands of Madeira (1420) and Azores (1427) were reached and began to be settled, producing wheat for export to Portugal. By the beginning of the reign of King Duarte I in 1433, the "Real" became the currency unit in Portugal, and remained so up to the 20th century.