While these preparations were going on the game of diplomacy was being played between the Courts of Spain and Portugal. King John of Portugal had the misfortune to be badly advised; and he was persuaded that, although he had lost the right to the New World through his rejection of Columbus’s services when they were first offered to him, he might still discover it for himself, relying for protection on the vague wording of the papal Bulls. He immediately began to prepare a fleet, nominally to go to the coast of Africa, but really to visit the newly discovered lands in the west. Hearing of these preparations, King Ferdinand sent an Ambassador to the Portuguese Court; and King John agreed also to appoint an Ambassador to discuss the whole matter of the line of demarcation, and in the meantime not to allow any of his ships to sail to the west for a period of sixty days after his Ambassador had reached Barcelona. There followed a good deal of diplomatic sharp practice; the Portuguese bribing the Spanish officials to give them information as to what was going on, and the Spaniards furnishing their envoys with double sets of letters and documents so that they could be prepared to counter any movement on the part of King John. The idea of the Portuguese was that the line of demarcation should be a parallel rather than a meridian; and that everything north of the Canaries should belong to Spain and everything south to Portugal; but this would never do from the Spanish point of view. The fact that a proposal had come from Portugal, however, gave Ferdinand an opportunity of delaying the diplomatic proceedings until his own expedition was actually ready to set sail; and he wrote to Columbus repeatedly, urging him to make all possible haste with his preparations. In the meantime he despatched a solemn embassy to Portugal, the purport of which, much beclouded and delayed by preliminary and impossible proposals, was to submit the whole question to the Pope for arbitration. And all the time he was busy petitioning the Pope to restore to Spain those concessions granted in the second Bull, but taken away again in the third.
This, being much egged on to it, the Pope ultimately did; waking up on September 26th, the day after Columbus’s departure, and issuing another Bull in which the Spanish Sovereigns were given all lands and islands, discovered or not discovered, which might be found by sailing west and south. Four Bulls; and after puzzling over them for a year, the Kings of Spain and Portugal decided to make their own Bull, and abide by it, which, having appointed commissioners, they did on June 7, 1494., when by the Treaty of Tordecillas the line of demarcation was finally fixed to pass from north to south through a point 370 leagues west of the Cape Verde Islands.