The Spanish treasure fleet, or West Indies Fleet (Flota de Indias, also called silver fleet or plate fleet; from the plata meaning "silver"), was a convoy system of sea routes organized by the Spanish Empire from 1566 to 1790, which linked Spain with its territories in the Americas across the Atlantic. The convoys were general purpose cargo fleets used for transporting a wide variety of items, including agricultural goods, lumber, various metal resources such as silver and gold, gems, pearls, spices, sugar, tobacco, silk, and other exotic goods from the overseas territories of the Spanish Empire to the Spanish mainland. Spanish goods such as oil, wine, textiles, books and tools were transported in the opposite direction.
The West Indies fleet was the first permanent transatlantic trade route in history. Similarly, the related Manila galleon trade was the first permanent trade route across the Pacific. The Spanish West and East Indies fleets are considered among the most successful naval operations in history and, from a commercial point of view, they made possible key components of today's global economic system.
Spanish ships had carried goods from the New World since Christopher Columbus's first expedition of 1492. The organized system of convoys dates from 1564, but Spain sought to protect shipping prior to that by organizing protection around the largest Caribbean island, Cuba, and the maritime region of southern Spain and the Canary Islands because of attacks by pirates and foreign navies. In the 1560s, the Spanish government created a system of convoys in response to the sacking of Havana by French privateers.
The main procedures were established based on 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.