Anne Hermle analyzes the development of Spanish bankruptcy law from the thirteenth century to the Ley Concursal of 2003. Her study focuses on identifying the central lines of development and on precisely distinguishing between genuinely Spanish legal innovations and foreign influences. Her approach, based on legal history and comparative law, demonstrates how Castilian norms shaped later Spanish law and which European legal systems exerted influence upon it. The author elucidates the fundamental structures of Castilian insolvency law-from debt bondage and the surrender of assets, through their problematic combination in the Nueva Recopilación , to the emergence of an independent commercial bankruptcy regime. She shows that the lived legal practice of the seventeenth century diverged dynamically from the formal statutory framework and was systematized by authors such as Salgado de Somoza. Particular attention is devoted to the Ordenanzas de Bilbao . Hermle examines their significance as the first systematic codification within the Spanish commercial sphere and refutes the assumption that they merely adopted French models. The codification efforts of the nineteenth century are likewise analyzed, including the influences of the French Code de Commerce as well as Belgian and Portuguese reform initiatives. Overall, the study reveals the development of bankruptcy law as a reflection of political and social transformations. It closes existing research gaps by presenting the entire historical trajectory in a coherent form and situating it within a broader European context.