Copena, DamiánGómez Martín, María2024-05-162024-05-162024Copena D, Gómez-Martín M. Spanish–French leech trade and its consequences: From the increase in medical demand to resource depletion and technical innovation. Medical History. 2024;68(1):42-59. doi:10.1017/mdh.2024.50025-7273http://hdl.handle.net/10347/33864This article studies the impact caused by the success and dissemination of Broussais’ theories on the use of leeches as a medical supply on Spanish–French trade relations, as well as its consequences for the Spanish market between 1821 and the 1860s. Analysing the documents produced by the different public administrations, together with newspaper and archival sources in both Spain and France and the literature and legislation of that period, allows us to understand the evolution of this trade and the heavy impact it had on the autochthonous population of this animal resource. The article reveals how, at the beginning of the 1820s, leeches became an important medical supply and how the demand for them increased significantly. This gave rise to a trade relation between Spain and France that led to the overexploitation of the resource, the issuing of regulations on the matter, and the search for technological solutions to increase the production of leechesengAtribución 4.0 Internacional© The Author(s), 2024. Published by Cambridge University Press. This is an Open Access article, distributed under the terms of the Creative Commons Attribution licence (http://creativecommons.org/licenses/by/4.0), which permits unrestricted re-use, distribution and reproduction, provided the original article is properly citedhttp://creativecommons.org/licenses/by/4.0/Hirudo medicinalisMedical inputMedicinal leechesMedical practiceHirudinicultureLeech feverRural industryRural innovationRural resourcesNineteenth centuryjournal article10.1017/mdh.2024.52048-8343open access