The death of Henry did not interrupt the progress of king John, who was very strict in his injunctions, not only to make discoveries, but to secure possession of the countries that were found.  The practice of the first navigators was only to raise a cross upon the coast, and to carve upon trees the device of Don Henry, the name which they thought it proper to give to the new coast, and any other information, for those that might happen to follow them; but now they began to erect piles of stone with a cross on the top, and engraved on the stone the arms of Portugal, the name of the king, and of the commander of the ship, with the day and year of the discovery.  This was accounted sufficient to prove their claim to the new lands; which might be pleaded, with justice enough, against any other Europeans, and the rights of the original inhabitants were never taken into notice.  Of these stone records, nine more were erected in the reign of king John, along the coast of Africa, as far as the cape of Good Hope.

The fortress in the isle of Arguin was finished, and it was found necessary to build another at S. Georgio de la Mina, a few degrees north of the line, to secure the trade of gold dust, which was chiefly carried on at that place.  For this purpose a fleet was fitted out, of ten large and three smaller vessels, freighted with materials for building the fort, and with provisions and ammunition for six hundred men, of whom one hundred were workmen and labourers.  Father Lafitau relates, in very particular terms, that these ships carried hewn stones, bricks, and timber, for the fort, so that nothing remained but barely to erect it.  He does not seem to consider how small a fort could be made out of the lading often ships.

The command of this fleet was given to Don Diego d’Azambue, who set sail December 11, 1481, and reaching La Mina January 19, 1482, gave immediate notice of his arrival to Caramansa, a petty prince of that part of the country, whom he very earnestly invited to an immediate conference.

Having received a message of civility from the negro chief, he landed, and chose a rising ground, proper for his intended fortress, on which he planted a banner with the arms of Portugal, and took possession in the name of his master.  He then raised an altar at the foot of a great tree, on which mass was celebrated, the whole assembly, says Lafitau, breaking out into tears of devotion at the prospect of inviting these barbarous nations to the profession of the true faith.  Being secure of the goodness of the end, they had no scruple about the means, nor ever considered how differently from the primitive martyrs and apostles they were attempting to make proselytes.  The first propagators of Christianity recommended their doctrines by their sufferings and virtues; they entered no defenceless territories with swords in their hands; they built no forts upon ground to which they had no right, nor polluted the purity of religion with the avarice of trade, or insolence of power.