A viceroy stands in for a king. In the 16th and 17th centuries the royal House of Asturias possessed a set of states whose common characteristic was that the king must rule them as though he were only king of each one. This was why, in their deeds, decrees and public declarations, the Asturias did not present themselves as kings of Spain but of Castille, Aragon, Naples, Sicily… It was no mere symbol, it was a reality which meant that throughout the 16th and 17th centuries sovereigns were obliged to multiply the royal person as often as necessary. This splendid study looks at this peculiar form of government. It follows chronologically the evolution of the system set up under the reign of Carlos I and adapted for use in Latin America when the colonies were transformed into the kingdoms of the Indies.