This book provides readers with the first biography in English on Leonor of England, bringing to life an understudied but fascinating figure who has been overshadowed by her famed parents and brothers. Leonor, also known as Eleanor, was queen consort of Castile (1170–1214), the wife of King Alfonso VIII and, as a Plantagenet, part of one of Europe’s most powerful dynastic networks.The chapters move chronologically through the queen’s life but centre around key themes such as her enigmatic dowry, her participation in European diplomacy and the development of courtly culture, the arts and literature in Castile. Drawing together a wide range of sources, from visual and literary accounts, royal itineraries and chronicles to her dower charter and legal texts, this study unveils Leonor as a powerful woman, well endowed with the means to exercise her authority with autonomy and decisiveness. She inaugurated the very first marriage alliance between England and an Iberian kingdom, promoted the family cult of martyr Thomas Becket in his adopted kingdom and contributed decisively to the consolidation of Burgos as the royal city and Castilian capital. Her arrival on the peninsula was key to the dynastic and identity projects that developed throughout the reign of Alfonso VIII. She was the very first queen consort in Castile to have a personal household fully funded by her dower resources and entirely at her service, which provided for a fabulous court attended by some of the best sculptors, musicians, troubadours, scholars, painters and minstrels.Leonor of England offers medieval students and scholars interested in queenship, women’s history, court culture and dynastic power more broadly a rare exploration of a figure who has remained in the shadows until now.