Juan of Castile, the only surviving child of the Catholic kings, received a rich inheritance, which, as is commonly believed, turned out to be an unbearable burden for her. For centuries, her fate remained a mystery to inquiring minds. Who is she really, just a weak-willed woman distraught from bitter losses or a wise and courageous politician who was ahead of her time? Was history fair to the ruler who vowed to save the crown and raise Spain from ruins, no matter what the cost?