History has dubbed these men and their companions Conquistadores from the later historical results, but it is unlikely that they viewed themselves as such in Columbus' time, being mainly interested in trade, gold, and colonization. Conquest is what they finally had to do to accomplish those goals in the lands of the natives. The resources for their explorations were provided by the monarchs of the major maritime countries: Ferdinand and Isabella of Spain, John II of Portugal (El Hombre, "the Man") and his successor, Manuel I of Portugal (O Afortunado, "the Fortunate), and Henry VII of England. These monarchs in particular made exploration and possession of the New World their main preoccupation. They often allocated unlimited funding to the expeditions. The professional mariners had to be first of all skilled ship captains. Second, they had to be able to navigate and be familiar with charts (a trade word for marine maps). Unlike today's navigators, who rely on admiralty charts and GPS's to determine position within a few feet, 15th century mariners made their own charts during exploration of unknown lands, the "Portolan charts," from which subsequent sailors to the region would take sailing directions. These were promulgated freely among the mariners, in contrast to the classical protocols of secrecy. The monarchs, who had formulated treaties among themselves, needed to know as quickly as possible who had discovered and claimed what land masses, and when. In Columbus' times, the ad hoc portolans were brought back to the office of the chief navigator (whether captain or some other officer) where they were transferred to a mappa mundi, "world map." This latter was on view to any professional who visited the office. The mariners all knew each other. When not voyaging they visited each other to donate their own data and read the latest data from the mappa kept there. The development of the latest maps was their common cause, otherwise they continued to compete. That Juan de la Cosa had his own office at Puerto de Santa Maria is thus made certain by the surviving map, published in 1500 under his name. That he did not himself draw the mappa is shown by the names assigned places on coasts he visited, and had a major hand in the nomenclature, such as the coast of Venezuela in 1499, but appear garbled or incomprehensible on the map, which must be attributed to a draftsman. De la Cosa knew what names he had assigned. That he supervised work on the mappa is shown by the fact that he wrote instructions on it concerning the data that was to appear there.