Yet even this intensity of commitment to adventure could not open new maritime routes without overcoming formidable material constraints. Availability of shipping was not usually an insuperable problem: explorers’ expeditions were infrequent and small — normally requiring between one and three ships with crews of twenty to fifty men per ship — and could be supported, on the scale required in this period, from within the shipping stocks of many western Mediterranean and Atlantic ports. Few explorers, however, had the financial resources to pursue their vocation at their own expense or the power to protect any discoveries they might make against the depredations of interlopers. The progress of exploration, therefore, relied on powerful patrons and wealthy backers. Dom Henrique used exploration as a means of diverting to potentially profitable ends his large and unruly household; his role as a patron of explorers, which he probably shared with other royal princes, was later exercised by King Joao II. John Cabot had a pension from Henry VII and a royal commission to explore similar to that of Columbus. It took Columbus longer to find a noble or royal patron than to reach the New World: he is said in early sources to have approached at least two noble houses and perhaps as many as four or five sovereigns. Except in Portugal, royal financial contributions were generally modest: the patron’s role was rather to confer legitimate title to the explorer’s potential rewards or profits.
Even in Portugal, merchant-backers were essential, like the Flemings and Genoese who promoted voyages to the Atlantic islands, or Fernao Gomes who bought up Dom Henrique’s rights to send expeditions along the African coast after the prince’s death, or the Florentines who financed Vasco da Gama’s mission to India, or the consortium of Azoreans and Englishmen who equipped north Atlantic voyages between 1501 and 1505. A large group of Bristol merchants, most of whom were engaged in the Icelandic trade and all of whom did business with Spain and Portugal, had combined in the 1480s and 1490s to finance the search for the Isle of Brasil. The Guerra brothers, hardtack suppliers of Seville, were prominent among financiers of voyages in Columbus’s wake. Columbus’s own backers belonged to two groups, most of whose members had previously collaborated in raising money for conquest and colonisation in the Canary Islands: royal treasury officials combined with Genoese and Florentine merchants of Seville. The financial role of the crown was largely limited to pourboires for Columbus and the promise that his backers would be indemnified from the royal share of the profits of indulgences.
The viability of the explorers’ enterprises is hard to assess. Dom Henrique’s navigators found places where slaves could be got and gold traded cheaply, but he seems for a long time to have subsidised exploration from the profits of his interests in fisheries, soap and — perhaps — corsairing. He died in debt but Fernao Gomes, for one, recognised the profitability of his endeavours. Despite heavy losses in shipping and men, the route Vasco da Gama found to India proved instantly profitable, thanks largely to the price differentials that made pepper an extraordinarily valuable cargo. The same cannot be said, however, of the exploration of the north Atlantic, where voyagers persevered with extraordinary tenacity in the investigation of cloud-banks and ice-floes. Columbus’s enterprise, though ultimately profitable, was jeopardised by paucity of returns. Anxiety to take home some evidence of potentially profitable trade or produce for his backers is a strong theme of the surviving version of his account of his first Atlantic crossing.