It must, however, be remarked, that it was a subject of great doubt and discussion to determine who this Ogane really was.
Although in possession of the extensive coast of Africa, the Portuguese had, as yet, no declared title to it, for that purpose, therefore, they appealed to religion or rather the superstition of the age.

It was a maxim, which the bigots of the Vatican had endeavoured strongly to inculcate, that whatever country was conquered from infidel nations, became the property of the victors.
This title was, however, not completed until it was confirmed by a special grant obtained from the pope, and accordingly the reigning monarch of Portugal, John II., obtained the grant of all the lands from Cape Bojador to the Indies inclusive.

Robertson, speaking of this grant, says, "extravagant as this donation, comprehending such a large portion of the habitable globe, would now appear even in catholic countries, no person in the fifteenth century doubted but that the pope, in the plenitude of his apostolic power, had a right to confer it." The grant was no sooner confirmed by the pope, than John hesitated not a moment to style himself Lord of Guinea, giving his commanders, at the same time, instructions that, instead of the wooden crosses, which it had hitherto been the custom to erect in token of conquest, pillars of stone should be raised twice the stature of a man, with proper inscriptions, and the whole surmounted by a crucifix inlaid with lead.

The first, who sailed from Elmina, for the purpose of planting these ensigns of dominion in regions yet undiscovered was Diego Cam, in 1484.

After passing Cape St.Catherine, he encountered a very strong current setting direct from the land, which was still at a considerable distance; on tasting the water, however, it was found to be fresh, from which the conjecture was drawn, that he was at the mouth of some great river, which ultimately turned out to be the fact.