The book "The History of the Reign of Ferdinand and Isabella the Catholic" is the third volume of a huge historical epic written by the outstanding American historian William Hickling Prescott. In this volume, the author deeply explores the events and characters during the reign of Ferdinand II of Aragon and Isabella I of Castile. Devoted to Catholicism and the introduction of the Inquisition, this royal couple marked the medieval history of Spain. Prescott details the political and cultural wars, changes, and achievements of this period, recreating the complex relationships between kingdoms and their important allies. This book is an important source for understanding the history of the 15th century and the influence of Ferdinand and Isabella on the further development of Europe.