central trading house and procurement agency for Spain's New World empire from the 16th to the 18th century. Organized in 1503 by Queen Isabella (Isabella I) in Sevilla (Seville), it was initially headed by Juan Rodríguez de Fonseca, her chaplain and former overseer of the Columbus expeditions, and it became an instrument of the Spanish crown's policy of centralization and imperial control. Besides serving as general overseer of commerce between Spain and its American possessions, as the 16th century progressed, the Casa began controlling the African slave trade, scheduling ships and shipping routes, collecting duties, and maintaining royal revenues. It also established navigational and cartography schools and began the Archives of the Indies, still an important source of colonial documents. The Casa de Contratación was moved from Sevilla to Cádiz in 1717 and abolished in 1790.