Sarmiento believed that he had obtained valuable information from the Incas and their guipus relative to these islands, which were also believed to be the outposts of a southern continent, and he thought that he could fix their position approximately.
In consequence, in the year 1567, he made a proposal for the re-discovery by the Spaniards of these distant lands. In one of his memorials to Philip II, he represented that he knew of many islands in the South Sea which were undiscovered by Europeans until his time, offering to undertake an expedition for their re-discovery with the approval of the Governor of Peru, who was then Lope Garcia de Castro.
Mendana's Fleet
Garcia de Castro willingly accepted Sarmiento's offer, and not only helped him in every way that lay in his power, but also offered him the sole command of the fleet. But, Sarmiento insisted that it should be entrusted to Alvaro de Mendana, a young nephew of Garcia de Castro.
This was probably a mistake on the part of Sarmiento, and was, no doubt, the cause of the failure of the expedition, and we may also attribute to his refusal of the sole command, the fact that his name has hitherto remained ignored not only in connection with this initiatory voyage, but also in connection with the further voyages of Mendana, Queiroz and Torres.
Sarmiento, however, stipulated that he should have the conduct of the discovery and navigation, and that no course should be altered without his consent.
The two ships of the expedition sailed from Callao, the port of Lima, in Peru, on the day of the feast of Santa Ysabel, the 19th of November, 1567, and Santa Ysabel became the patroness saint of the expedition.
Sarmiento intended to steer W.S.W. until he reached the tropic of Capricorn,* and this direction was kept until the 28th of November.