The Spanish institutions of the Ancien Régime were the superstructure that, with some innovations, but above all through the adaptation and transformation of the political, social and economic institutions and practices pre-existing in the different Christian kingdoms of the Iberian Peninsula in the Late Middle Ages, presided over the historical period that broadly coincides with the Modern Age: from the Catholic Monarchs to the Liberal Revolution (from the last third of the 15th century to the first third of the 18th century) and which was characterized by the features of the Ancien Régime in Western Europe: a strong monarchy (authoritarian or absolute), a estamental society and an economy in transition from feudalism to capitalism.