MOTIVES AND SIGNIFICANCE

As we have seen in Chapter 4, the Spanish crown's overriding insistence on the need to impose an effective control upon the extraction of silver from the mines of New Spain and Peru, coupled with its aspiration to ensure the safe and regular despatch of treasure to Spain, underpinned the development by the second half of the sixteenth century of a trans-Atlantic commercial structure whose three administrative centres were Lima, Mexico and Seville, and whose principal ports were Callao (linked to Spain via Panama-Portobelo), Veracruz and Seville-Cádiz. In some respects this restrictive system was less rigid than it might appear super-ficially, for, as Chapter 5 has demonstrated, complex networks of inter-American trade provided some scope for the agricultural and natural products of regions isolated from the official routes of trade with the metropolis to eventually reach the trade fairs of Portobelo and Veracruz for shipment to Europe. At the Spanish end of the system, too, a wide range of non-Andalusian products (for example, iron from the Basque region and silk goods from Valencia) were taken by local traders and coastal shippers to Seville-Cádiz for onward despatch to America. It remains true, nevertheless, that the Hapsburg policies developed for the regulation of both economic life in America and commercial relations between Spain and America, although in one sense obeying a coherent pattern of historical development—the conquest of Peru from Panama, for example, provided a logical basis for the growth of a commercial network which linked the viceroyalty to Spain via the isthmus rather than the Strait of Magellan—marginalised vast territorial expanses, particularly in South America, from the permitted routes of direct trade.