The conquests would have been impossible without the European equipment, metal and supplies that Spanish merchants delivered to America; nor, without the prospect of a Europeanstyle life that the merchandise held out, would the conquerors have had as strong a motivation for their campaigns. Thus merchants are woven into the fabric of the conquest as one of its characteristic phenomena, and their letters are most informative, throwing the process into quite a different light, with their talk of horseshoes and nails, casks of wine, or considerations of currency and credit. Sometimes a merchant would actually accompany an expedition, but his more usual station was at the base of operations, where he would receive shipments from Spain, sell them or send them on to the conquerors, and send remittances back. When the focus of conquest in Tierra Firme shifted to Panama and the west coast, the merchants stayed for a while in Nombre de Dios on the Caribbean, where we find Martin de Zubizarreta, writer of the present letter. It may be viewed as a sequel to Letter 2, which is from the same region a year earlier. By now Governor Pedrarias has gone to assert his authority in Nicaragua, but the limitations of Nicaraguan wealth are already becoming apparent, and attention is shifting towards Peru, Pizarro and Almagro. A little later, as Peru becomes dominant, the merchants will make Panama their base, and subsequently Lima as well.

Import merchants in the Indies at this time were usually representatives of trans-Atlantic commercial networks with headquarters in Seville. Sometimes the merchants in America were partners, having made an investment; or sometimes, as here, they were factors who were paid a salary or commission. In either case they were junior men, quite dependent on the s.enior figures in Seville for their advancement. They could not make too many decisions independently, and they were under pressure to sell quickly and send a steady stream of money back. Their letters show this state of things in their often wavering tone and extraordinarily weak statements: ‘I believe that pleasing God I will sell everything … as quickly as I can.’