Leonardo da Vinci spent the last three years of his life as a guest of the king of France in Amboise, and the last masterpiece he produced was the project for a royal residence at Romorantin. It was to be a vast complex of buildings and gardens crossed by the Saudre River, and was to incorporate the old chateau of the ancestors of Francis I. "The eve of St. Anthony's Day I returned from Romorantin to Amboise, and the king had left Romorantin two days before," wrote Leonardo in January 1517. In 1518 a canal project at Romorantin was financed. But in the year of Leonardo's death, 1519, the project for the palace was abandoned and the king decided to build the castle of Chambord instead. The loss of the Romorantin Palace is comparable in magnitude to that of Leonardo's wall paintin of the Battle of Anghiari--perhaps even more tragic, for little influence could come from an abandoned work of architecture, the conception of which was soon forgotten. The remains of the portion that was built stood ten feet high until the time of the French Revolution. Mr. Pedretti has traced the records of their existence, brought together all possible references to the project in Leonardo's manuscripts, and identified the site of the proposed construction. The style and sources of the project are shown through a wealth of illustrations which bring to life the image of Leonardo's last dream.