The evolving structure of colonial government was not fully formed until the third quarter of the 16th century; however, "los Reyes Católicos" designated Juan Rodríguez de Fonseca to study the problems related to the colonization process. Rodríguez de Fonseca effectively became minister for the Indies and laid the foundations for the creation of a colonial bureaucracy, combining legislative, executive and judicial functions. Rodríguez de Fonseca presided over the council, which contained a number of members of the Council of Castile ("Consejo de Castilla"), and formed a "Junta de Indias" of about eight counsellors. Emperor Charles V was already using the term "Council of the Indies" in 1519.