Note:  Do not rely on this information. It is very old.

Galleon

Galleon, anciently, a ship of war of the largest size, with three or four decks of guns; but, in the 18th century, one of the large Spanish merchantmen employed in regular voyages to the Indies and elsewhere, and usually having four decks, and carrying guns. Until after the commencement of the present century the galleons sailed yearly from Cadiz, and were away for about two years. The chief ones brought home the produce of the Potosi silver mines, and also much gold, precious stones, wool, quinine, skins, leather, etc. The number of galleons varied, and was greatest in time of war; but a single one with her cargo was often worth nearly two millions sterling.