大東群島
These groups were collectively called "Islas del Arzobispo" (Archbishop Islands) in Spanish sources of the 18th–19th century. This name is most likely due to an expedition organized by the Arzobispo (Archbishop) Pedro Moya de Contreras, Viceroy of New Spain, to explore the northern Pacific and the islands of Japan. Its main objective was to find the long sought and legendary islands of "Rica de Oro" (Rich in Gold), "Rica de Plata" (Rich in Silver) and the "Islas del Armenio" (Islands of the Armenian). After several years of planning and frustrated attempts the expedition finally set sail on 12 July 1587 commanded by Pedro de Unamuno. Even if it did revisit the Daitō Islands, already charted by Bernardo de la Torre in 1543, the expedition could not find the wanted islands after searching the positions where they were charted in contemporary references. Japanese maps at the time seem to have been rather inaccurate and therefore considered by some to be deliberately misleading. It is thought that this was an attempt to discourage colonization attempts by foreign nations. Frederick William Beechey used the Spanish name as late as 1831 and believed that the Japanese "Boninsima" referred to entirely different islands.