Spanish treasure fleet The Spanish treasure fleet , also called silver fleet , plate fleet ( from the Spanish " plata " meaning " silver " ) , or West Indies Fleet from Spanish " Flota de Indias " , was a convoy system adopted by the Spanish Empire from 1566 to 1790 . The convoys were general purpose cargo fleets used for transporting a wide variety of items , including agricultural goods , lumber , various metal resources , luxuries , silver , gold , gem s , pearls , spices , sugar , tobacco , silk , and other exotic goods from the Spanish Empire in the Americas to Spain . Passengers and goods such as textiles , books and tools were transported in the opposite direction . History . Spanish ships had brought goods from the New World since Christopher Columbus ' s first expedition of 1492 . The government started a system of convoys in the 1560s in response to the sacking of Havana by French privateer s . The main procedures were established after the recommendations of Pedro Menéndez de Avilés , an experienced admiral and personal adviser of King Philip II . The treasure fleets sailed along two sea lanes . The main one was the Caribbean Spanish West Indies fleet or " Flota de Indias " , which departed in two convoys from Seville , where the " Casa de Contratación " was based , bound for ports such as Veracruz , Portobelo and Cartagena before making a rendezvous at Havana in order to return together to Spain . A secondary route was that of the Manila Galleon s or " Galeón de Manila " which linked the Philippines to Acapulco in Mexico across the Pacific Ocean . From Acapulco , the Asian goods were transhipped by mule train to Veracruz to be loaded on to the Caribbean treasure fleet for shipment to Spain . To better defend this trade , Pedro Menéndez de Avilés and Álvaro de Bazán designed the definitive model of the galleon in the 1550s . Spain strictly controlled the trade through the " Casa de Contratación " based in Seville . By law , the colonies could trade only with the one designated port in the mother country , Seville . Maritime archaeology has shown that the quantity of goods transported was usually much higher than that recorded at the " Archivo General de Indias " . Spanish merchants and Spaniards acting as fronts ( " cargadores " ) for foreign merchants resorted to contraband to transport their cargoes untaxed . The Crown of Spain taxed the wares and precious metals of private merchants at a rate of 20 % , a tax known as the " quinto real " ( royal fifth ) . Spain became the richest country in Europe by the end of the 16th century , but the Habsburgs used the wealth to fight wars in the 16th and 17th centuries against the Ottoman Empire and with most of the major European powers . Supernormal inflation in the 17th century , caused by the flow of precious metals from the American colonies gradually damaged the Spanish economy . As a consequence , following a series of non - payments of debts , Spain lost financial support from European bankers by 1690 . Nonetheless , the Spanish monopsony over its West Indies colonies lasted for over two centuries . The exports ' economic importance also declined with the drop of production of the American precious metals mines , such as Potosí . Numbering just 17 ships in 1550 , the fleets expanded to more than 50 much larger vessels by the end of the century . By the second half of the 17th century , that number had dwindled less than half of its peak , with many of its remaining ships old and in poor repair . As economic conditions gradually recovered from the last decades of the 17th century , the fleet operations slowly expanded again , once again becoming prominent during the reign of the Bourbons in the 18th century . The Spanish trade of goods and precious metals was threatened until the mid - 18th century by Spain ' s colonial rivals who seized islands as bases along the Spanish Main and in the Spanish West Indies . The English acquired small islands like St Kitts in 1624 , expelled in 1629 they returned in 1639 and seized Jamaica in 1655 . French pirates established themselves in Saint - Domingue in 1625 , were expelled only to return later and the Dutch seized Curaçao in 1634 . In 1739 , British Admiral Edward Vernon raided Portobello , but in 1741 his massive campaign against Cartagena de Indias ended in defeat with heavy losses of men and ships . Temporary British seizures of Havana and Manila ( 1762 - 4 ) , during the Seven Years ' War , were dealt with by using more , smaller fleets visiting a greater variety of ports . Charles III began loosening the system in 1765 . In the 1780s Spain opened its colonies to free trade . In 1790 , the " Casa de Contratación " was abolished , bringing to an end the great general purpose treasure fleets . Thereafter small groups of naval frigates were assigned specifically to transferring bullion as required . Despite the general perception that many Spanish galleons were captured by Dutch and English privateers , few fleets were actually lost to enemies in the course of the " flota ' s " two and a half centuries of operation . Only Piet Hein managed to capture the fleet in 1628 and bring the whole cargo safely to the Dutch Republic . In 1656 and 1657 Robert Blake attacked the fleet , but the Spaniards saved most of the silver on board and the English admiral only managed to capture a galleon . The 1702 treasure fleet was destroyed in the Battle of Vigo Bay during the War of the Spanish Succession , when the fleet was surprised at port unloading its goods , but the Spanish sailors had already unloaded most of its cargo . None of these attacks took place in open seas . In the case of the Manila galleons , only four were ever captured by British warships : The " Santa Anna " by Thomas Cavendish in 1589 , the " Encarnación " in 1710 , the " Covadonga " by George Anson in 1743 , and the " Santísima Trinidad " in 1762 . Two other British attempts were foiled by the " Rosario " in 1704 and the " Begonia " in 1710 . These losses and those due to hurricanes were important economic blows to trade when they occurred . The treasure fleets , however , must be counted as among the most successful naval operations in history . Moreover , from a commercial point of view , some key components of today ' s world economic system were made possible by the success of the Spanish treasure fleets . Wrecks of Spanish treasure ships , whether sunk in naval combat or by storms ( those of 1622 , 1715 ( 1715 Treasure Fleet ) and 1733 being among the worst ) , are a prime target for modern treasure hunters . Many , such as the " Nuestra Señora de Atocha " , have been salvaged . The flow of Spanish treasure . Walton gives the following figures in pesos . For the 300 - year period the Peso or Piece of Eight had about 25 grams of silver , about the same as the German Thaler , Dutch rijksdaalder or the US Silver dollar . A single galleon might carry 2 million pesos . Of the estimated 4 billion pesos produced during the period 2 . 5 billion was shipped to Europe , of which 500 million was shipped around Africa to Asia . Of the remaining 1 . 5 billion 650 million went directly to Asia from Acapulco and 850 million remained in the Western Hemisphere . Little of the wealth stayed in Spain . Of the 11 million arriving in 1590 , 2 million went to France for imports , 6 million to Italy for imports and military expenses , of which 2 . 5 went up the Spanish road to the low countries and 1 million to the Ottoman Empire . 1 . 5 million was shipped from Portugal to Asia . Of the 2 million pesos reaching the Dutch Republic in that year , 75 % went to the Baltic for naval stores and 25 % went to Asia . The income of the Spanish crown from all sources was about 2 . 5 million pesos in 1550 , 14 million in the 1590s , about 15 million in 1760 and 30 million in 1780 . In 1665 the debts of the Spanish crown were 30 million pesos short - term and 300 million long - term . Most of the New World production was silver but Colombia produced mostly gold . After about 1730 Brazil began producing gold . The following table gives the estimated legal production and necessarily excludes smuggling which was increasingly important after 1600 . The crown legally took one fifth at the source and obtained more through other taxes .