The Greek geographers had postulated that there must be a great southern continent to balance the land masses in the northern hemisphere. This idea of a large southern mass of lands known as Terra Australis Incognito long persisted and appears on the maps drawn by European armchair geographers. It was finally narrowed down to the approximate size of the actual continent of Antarctica by Captain Cook, late in the eighteenth century. Although this continent remained elusive, there were those who believed in it firmly. At various times Australia, the Solomons, the New Hebrides, and New Zealand were hopefully labeled as part of this continent. Some of the last Spanish expeditions of pure exploration were conducted by Mendafia and Quiros in search of this continent. The first of these expeditions, under Alvaro de Mendaña in 1567, managed to sail between the Tuamotus and the Marquesas as well as near the Society Islands without sighting land. They finally sighted one of the Ellice Islands. From here they sailed on to islands that were later named the Solomons because of stories of fabulous wealth told by the returning seamen. The Solomons were not rediscovered until 1767 and continued to be one of the many groups of semi-mythical islands that cluttered up the charts. After abandoning an attempt to establish a colony there, Mendana turned northward, skirting the western side of the Gilberts and Marshalls until he reached Urdaneta's Passage and was able to return to the Americas with the aid of the westerlies. Wake was discovered on this voyage, although not revisited until 1796.
After many disappointments Mendana again sailed onto the Pacific with Pedro Fernandez de Quiros as his pilot in 1595. This expedition discovered and named the Marquesas after the wife of the Viceroy of Peru, the Marquesas de Mendoza. The Santa Cruz Islands were at first mistaken for the Solomons. Mendana died after an unsuccessful attempt to found a colony, and the survivors proceeded to Manila with much difficulty.
In spite of the failure of the previous expedition, Quiros was fired by zeal to bring Christianity to the natives of the Pacific and to discover the unknown southern continent. He pestered the Viceroy of Peru, the Council of the Indias, the King of Spain, and the Pope until he was given command of an expedition that sailed from Callao in 1605. Quiros, an idealist, issued orders that there was to be no swearing, no gambling, and no blaspheming. Daily services were to be held, and the natives were to be treated with humanity. After discovering some small islands near Tahiti, thus contributing more semi-mythical islands to the Pacific charts, he finally, in 1606, discovered the New Hebrides.
A colony was founded on Espiritu Santo, named Australia del Espiritu Santo. The colony was called New Jerusalem; the town, Vera Cruz; the river, Jordan; and the bay, St. Philip and St. James, names that reflect the religious zeal that now took complete possession of Quiros. The colony broke up because of mutiny, native troubles, and disease. Quiros returned to Acapulco by Urdaneta's Passage while his chief pilot, Torres, continued exploration westward. Torres discovered and sailed through the strait between Australia and New Guinea that bears his name. The fate of this discovery illustrates a new phase of Pacific cartography. The Spanish empire had by this time passed its zenith and wished to hold what it possessed without the development of new discoveries. As a result, the discovery of Torres Strait was buried in the archives and did not become known to the world until much later when the English, in 1762, captured a map in Manila showing New Guinea to be an island, and the geographer Dalrymple labeled the passage Torres Strait.
During the Spanish Period, English and French pirates or freebooters made some discoveries that appeared on charts. Sir Francis Drake, in 1578, raided the Spanish settlements in the Americas and crossed the Pacific on his return to Europe. His real contribution to cartography was the discovery of a route south of Terra del Fuego. Other raids, of which that of Thomas Cavendish in 1586-1588 is outstanding, contributed to the general knowledge of the Pacific; but as a result the Spanish became even stricter in their release of information regarding the Pacific.