Convoy System in Spain
Unlike the guild, the convoy system was less a product of Spanish social structure than of the efforts of Barbary pirates and French rivals to seize the incoming treasure from New Spain. Enemy attacks required an effective defense. After French pirates seized the booty that Cortés sent back from Tenochtitlan, merchants took the initiative, financing a squadron to protect their vessels off the Spanish coast as early as 1521. Soon after, the Crown required merchantmen to sail in groups of 10, and separate warships were assigned to the convoys as escorts. The system only jelled in 1564-66, when a specific schedule for the ships was promulgated. The flota (fleet), leaving in April, was to sail to the Caribbean with Veracruz as its main destination. It was protected by two warships. The galeones (galleons) were to sail in August for the Isthmus of Panama, reaching Portobelo with a few vessels going to Cartagena. The traders transshipped goods across Panama and along the Pacific coast as far as Arica, south of Lima. The galeones convoy included eight warships, since, until the 1670s, Peru sent more silver back to Spain than did New Spain. The two convoys, called the Armada de la guardia de las Indias, spent the winter in America and joined each other the following March at Havana to return to Spain before hurricanes threatened their passage.

There was always an illegal effort to cram merchandise onto the warships, reflecting the passion for trade that so many of New Spain's inhabitants shared. But despite overloading and problems of refitting and obtaining experienced crews, the convoy system did a splendid job of protecting the cargoes. Spain's enemies only captured the Indies treasure twice ( 1628, 1656). In the Pacific, the Manila galleon itself was armed. Leaving the Philippines in June to avoid typhoons, it reached Acapulco, the only legal port of arrival, in January. It carried silks and brocades, linens and jewelry, porcelain and furniture from China, as well as exquisite luxury goods and spices from Japan, India, and Indonesia. These goods were reexported to Central America and Peru until 1631, when Spain prohibited this practice. The Armada de la mar del Sur, consisting of five galleons, protected the coastal Pacific trade. Few galleons were captured here, either. The system opted for security at the expense of flexibility. It made sense in the sixteenth century when the Seville merchants and the Crown filled the ships and kept the convoys to their prescribed annual schedule. In the seventeenth century they lacked the resources or the will to do either.