The landlord system and the limits of liberal Spanish monetary policy in the first half of the 19th centuryThis paper aims to deepen the understanding of the transition from traditional to modern monetary systems and its impact on economic growth in the Spanish economy over the first half of the nineteenth century. The main sources on which the study of this period’s monetary policy is based, are, among others, the proceedings of the parliamentary committee; during the Trienio Liberal, these related to a draft for the complete reform of the monetary system inherited from the Antiguo régimen, whose results would be constrained by three factors: firstly, by the persistence of traditional institutions; secondly, by difficulties in linking this monetary reform with the discussions that were taking place in the more developed countries, particularly in England; and, thirdly, the short duration of the period in which it took place, and the restoration of the old monetary policy with the Tarifa de Tolosa in 1823. / Este trabajo pretende profundizar en la comprensión, para el caso español, del tránsito del sistema monetario tradicional al moderno y sus repercusiones en el crecimiento económico de la economía española a lo largo de la primera mitad del siglo XIX. Tomamos como punto de inflexión el Trienio Liberal y su proyecto de reforma del sistema monetario español heredado del Antiguo Régimen. A continuación analizamos la persistencia del sistema monetario tradicional hasta la reforma del 1848 y la estrecha relación entre los límites de la política monetaria liberal y la pervivencia de unas estructuras productivas y sociales tradicionales