Soon after the departure of Diaz, King John dispatched Pedro de Covilham and Alphonso de Payva, both well versed in the Arabic language, with orders to travel by land into the east, for the discovery of the country of _Presbyter_, or _Prester John_, and to trace the steps of the lucrative commerce then carried on with India by the Venetians for spices and drugs; part of their instructions being to endeavour to ascertain the practicability of navigating round the south extremity of Africa to the famed marts of Indian commerce, and to make every possible inquiry into the circumstances of that important navigation. Some writers have placed this journey as prior in point of time to the voyage of Diaz, and have even imagined that the navigator was directed or instructed by the report which Covilham transmitted respecting India. Of the relation of this voyage by Alvarez, which Purchas published in an abbreviated form, from a translation out of the Italian in the collection of Ramusio, found among the papers of Hakluyt, Purchas gives the following character: "I esteem it true in those things which he saith he saw: In some others which he had by relation of enlarging travellers, or boasting Abassines, he may perhaps sometimes rather _mendacia dicere_, than _mentiri_." To _tell_ lies rather than _make_ them. Covilham, or Covillan, was born in a town of that name in Portugal, and went, when a boy, into Castile, where he entered the service of Don Alphonso, duke of Seville. On a war breaking out between Portugal and Castile, he returned into his native country, where he got into the household of King Alphonso, who made him a man-at-arms. After the death of that king, he was one of the guard of King John, who employed him on a mission into Spain, on account of his knowledge in the language. He was afterwards employed in Barbary, where he remained some time, and acquired the Arabic language, and was employed to negotiate a peace with the king of Tremesen. He was a second time sent into Barbary on a mission to King _Amoli-bela-gegi_, to procure restitution of the bones of the infant Don Fernando, in which he was successful. After his return, he was joined in commission, as before-mentioned, with Alphonso de Payva, and these adventurous travellers left Lisbon in May 1487. Covilham was furnished with a very curious map for these times, by the Prince Emanuel, afterwards king of Portugal, which had been copied and composed, with great care and secrecy, by the licentiate Calzadilla, afterwards bishop of Viseo, assisted by Doctor Rodrigo, and a Jewish physician named Moses; which map asserted the practicability of passing by sea to India round the southern extremity of Africa, on some obscure information which had been collected by those who constructed it.