This establishment had been scarcely formed, when an important event took place, which afforded a favourable opportunity and pretext for laying the foundation of the Portuguese empire in Africa.  Bemoy, a prince of the Jaloofs, arrived at Arguin, as a suppliant for foreign aid, in recovering his dominions from a more powerful competitor or usurper.  He was received with open arms, and conveyed to Lisbon, where he experienced a brilliant reception, his visit being celebrated by all the festal exhibitions peculiar to that age, bull-fights, puppet-shows, and even feats of dogs.  On that occasion, Bemoy made a display of the agility of his native attendants, who on foot, kept pace with the swift horses, mounting and alighting from these animals at full gallop After being instructed in the Christian religion, he was baptized, and did homage to the king and the pope, for the crown, which was to be placed on his head; for this purpose a powerful armament under the command of Pero vaz d’Acunha, was sent out with him, to the banks of the Senegal.

The circumstance, which tended more particularly to inflame the pious zeal of the Christian monarch, was the information, that to the east of Timbuctoo there was a territory inhabited by a people who were neither moors nor pagans, but who, in many of their customs resembled the Christians.  It was immediately inferred, that this could be no other than the kingdom of the mysterious personage known in Europe, under the uncouth appellation of Prester John.  This singular name seems first to have been introduced by travellers from eastern Asia, where it had been applied to some Nestorian bishop, who held there a species of sovereignty, and when rumours arrived of the Christian king of Abyssinia, he was concluded to be the real Prester John.  His dominions being reported to stretch far inland, and the breadth of the African continent being very imperfectly understood, the conclusion was formed, that a mission from the western coast might easily reach his capital.  It does not fully appear, what were the precise expectations from an intercourse with this great personage, but it seems to have been thoroughly rooted in the minds of the Portuguese, that they would be raised to a matchless height of glory and felicity, if they could by any means arrive at his court.  The principal instruction given to all officers employed in the African service, was, that in every quarter, and by every means, they should endeavour to effect this discovery.  They accordingly never failed to put the question to all the wanderers of the desert, and to every caravan that came from the interior, but in vain, the name had never been heard.  The Portuguese then besought the natives at all events, into whatever region they might travel, studiously to inquire if Prester John was there, or if any one knew where he was to be found, and on the promise of a splendid reward, in case of success, this was readily undertaken.