A Treasury in Transition: Changes and Continuity in the Management of Castilian State Finances During the Reign of Isabella I (1474–1504)

The evolution of the Royal Treasury during the reign of Isabella I (1474–1504) is an increasingly well-known field of study, as a result of the historiography dedicated to the state-building process in the Crown of Castile during the transition from medieval times to the early modern period. This is also in line with the progress made in the study of treasury and tax structures in Western Europe between the thirteenth and eighteenth centuries. Thanks to work carried out since the 1960s, we have extensive knowledge about the sources of ordinary and extraordinary income that fed the Castilian royal exchequer in the late fifteenth century, how income developed, the mechanisms used for its administration, and the main items of expenditure. Progress has also been made in studying aspects of the political culture and how taxes were legitimised related to the negotiation of taxation and the search for consensus with the powers of the kingdom in a chronology that allows lines of continuity to be drawn between the systems observed in the late medieval period and those of modern times. Finally, in recent years, the development of tax and finance structures has been looked at in more depth from a regional perspective, in an attempt to move away from the “national” vision and focus instead on the links established between royal power, the treasury and society in areas forming part of the Crown of Castile such as Galicia, the Cantabrian region, Biscay, New Castile, Lower Andalusia and Granada, to name just a few examples analysed in recent comprehensive studies. All of this has improved our understanding of the differences and similarities in the system of taxation and the royal treasury in the different areas that made up the Crown of Castile in its almost definitive territorial formation in the thirteenth century, as well as the contribution to the kingdom as a whole by each separate fiscal area. It has also served to expand the analysis, offering complementary perspectives that allow for the integration of elements such as business, tax legitimacy and how power was exercised in its many manifestations. Based on these general parameters, this chapter aims to present a comprehensive review of the advances in research made in recent years (until 2020) in relation to the income and expenditure management structures implemented during the reign of Isabella I. This is vitally important if we are to understand the transition from the late medieval tax and finance system to more complex systems, whose development enabled the Castilian monarchy to achieve its political objectives and position itself at the beginning of the sixteenth century as one of the most powerful states, in terms of tax and finance, in Western Europe.