John king of Portugal was so much concerned for having allowed this new empire to go from himself, that he ordered preparations to be made for invading the new discoveries, pretending that they belonged of right to him. At the same time he sent Ruy de Sande as his ambassador to their Catholic majesties, who was desired to express his satisfaction at the success of the voyage of discovery, and that the king his master made no doubt, if Columbus had made the discovery of any countries and islands which belonged to the crown of Portugal, their majesties would so act towards him as he would to them on a like occasion: That, being informed their majesties meant to prosecute discoveries due west from the Canary islands, without turning to the southwards; the king of Portugal required their majesties would direct their admiral not to pass these bounds to the south, and he should enjoin his commanders not to go beyond the same bounds to the north. Before the arrival of Ruy de Sande, a report had reached court that the king of Portugal proposed to send a fleet the same way with the Spaniards, on purpose to take possession of the new discovered lands. To counteract this hostile indication, Fonseca was instructed to provide the fleet of Columbus with ample means of offence or defence, and to hasten its departure. Their majesties likewise sent Lope de Herrera, a gentleman of their court, as envoy to Lisbon, with instructions to return their thanks to the king of Portugal for his courtesy to the admiral, when at Lisbon, and to require him to forbid his subjects from going to any of the newly discovered islands and continents, which were their undoubted property. Herrera was instructed to represent the extraordinary care which their Catholic majesties had taken, in charging the admiral not to touch at the gold mines of Guinea, or at any other of the Portuguese discoveries. When Ruy de Sande had delivered his embassy, as above, he desired leave to export certain articles, needed as he said, for an expedition which the king of Portugal intended against the Moors, which he gave out as a cover for the intended voyage of discovery to the west. He likewise demanded that the Spaniards should be restrained from fishing off Cape Bojador until it were settled amicably between the two crowns whether that were lawful.

As Lope de Herrera had set out for Portugal before Ruy de Sande had reached the Spanish court; King John, on learning the purport of his embassy, sent Edward Galvan to give him notice of the commission entrusted to Sande, respecting the discoveries of Columbus; and, without permitting Herrera to use his credentials, gave assurance that the king of Portugal would send no ships on discovery for sixty days120, as he meant to send an embassy to their Catholic majesties on that particular subject. While this dispute was in agitation, the king of Portugal complained to the pope that their Catholic majesties interfered with his discoveries and privileges, protesting against the bulls, as trenching upon his limits, and requiring a different line of demarcation to prevent the troubles which might ensue between the subjects of the two crowns. The pope answered, that he had ordered a meridianal line from pole to pole on purpose to mark out what belonged to each of the sovereigns; and again issued another bull on the 26th of September of the same year, in which he granted to the kings of Spain all that should be discovered and conquered in the islands to the east, west, and south, not already possessed by any other Christian prince. This gave much dissatisfaction to the court of Portugal, which alleged that it was wronged by the pope, and the meridian of separation ought to be drawn much farther westwards121.

About this time, advice was brought of Martin Alonso Pinzon having arrived with the caravel Pinta in one of the ports of Galicia, after escaping with much difficulty from several dreadful storms. He died soon after; and some say it was of grief, for a reprimand he received from court for his disobedience to the admiral, and deserting him during the voyage; and because their majesties refused to see him, unless introduced by Columbus.

After the sixty days assigned by the king of Portugal were elapsed122, their Catholic majesties sent Garcia de Herrera, one of the gentlemen of their household, to require the court of Portugal to refrain from encroaching on the limits granted by the Pope to the crown of Castile and Leon. Their majesties afterwards sent Don Pedro de Ayala and Garcia Lopez de Carvajal, to say that they were willing to admit all honourable means of continuing in friendship with the king of Portugal, but they were satisfied nothing belonged to his crown in the ocean, except Madeira, the Azores, and the Cape Verde islands, as far as Guinea and the gold mines. They even offered to submit the difference between the crowns on this subject to the decision of persons nominated on both sides, with power to the arbitrators to name an umpire, if they could not agree, or to have the matter at issue debated at the court of Rome or any other neutral place, as their majesties had no wish to invade the rights of others, or to permit the infringement of their own. The Portuguese court proposed to divide the ocean by a straight line, or parallel drawn west from the Canaries, leaving all to the north of that line to the crown of Castile and Leon, and all to the south to belong to Portugal. At length, after tedious negotiations, a congress took place at Tordesillas, in which, after long debates, it was agreed on the 7th June 1473123, that the meridianal line of division should be established 370 leagues farther west than that mentioned in the Popes bull from the islands of Cabo Verde; all to the west of which was to belong to Spain, and all eastwards to Portugal; yet leaving it lawful to the subjects of Spain to sail through the seas thus allotted to Portugal, following their direct course; but neither party to trade or barter beyond their own limits.

Before leaving Barcelona, the admiral placed his sons Don James and Don Ferdinand as pages in the service of prince John; and having received his commission of admiral and viceroy, extending as large as the papal grant, he repaired to Seville to expedite his second voyage to the new world. He here applied himself to procure able pilots, and to review the men who were to embark in the expedition, in the presence of the controller Soria. All persons were prohibited from carrying out any goods for barter, and it was ordered that every thing belonging to their majesties or to private persons should be entered at the custom-house, both in Spain and the Indies, under the penalty of confiscation. The admiral had instructions to muster his men as soon as he arrived at Hispaniola, and to do the same as often as he thought proper, with power to regulate their pay. He was likewise authorized to nominate alcaldes and alguazils, or magistrates, in the islands and other parts, with power to try causes both civil and criminal, from whom appeals might be made to himself. In the first instance he was allowed the direct nomination of all the aldermen, common council-men, and other officers, in any town; but in future he was to nominate three persons to every vacancy, out of whom their majesties were to appoint one to the office. All proclamations, patents, injunctions, orders, or other public writings, were to be made in the name of their majesties, signed by the admiral, and countersigned by the secretary or clerk by whom they were written, and sealed on the back with the royal seal. As soon as he landed, a custom-house was to be built, in which all their majesties stores were to be secured under their officers, over whom the admiral was to have supreme command; and all trade was to be conducted by him, or by such persons as he might appoint, with the assistance of the royal inspector and controller. The admiral was to have the eighth part of all profit, paying the eighth of all goods carried over for barter; first deducting the tenth which he was entitled to of all things according to his contract. And finally, he was authorized to send ships to any other part, according as he saw proper or convenient.