This audiobook is narrated by an AI Voice. This work traces the life of Isabel I of Castile, one of the most decisive and controversial figures in European history. From her childhood marked by dynastic intrigues to her consolidation as queen, the book shows how a seemingly sidelined young princess became the axis of peninsular unification and a protagonist in the birth of the Hispanic monarchy. Throughout its pages, the reader accompanies Isabel in her great decisions: the War of Succession, her marriage to Fernando of Aragon, the conquest of Granada, the support for Christopher Columbus and the discovery of America, as well as the establishment of the Inquisition and the expulsion of the Jews—analyzed without hiding either their lights or their shadows. At the same time, a window opens to her most intimate facet: the mother, the wife, the deeply religious woman who lived between the duty of the Crown and her own convictions.