Two of the most notable figures from the Middle Ages the volatile, brilliant Abelard and the equally brilliant Heloise became the parents of their son Astralabe before Abelard s infamous, brutal castration. The couple spent the rest of their lives as monastics, in each other s orbits if not in shared presence, as they became movers in the glittering monastic world of the early twelfth-century France. What happened to their strangely named Astralabe? Astralabe: The Life and Times of the Son of Heloise and Abelard rescues the lost son from footnotes and fiction and attempts to tell instead the story of a real man living in Europe in the twelfth century. This book assembles the references to Astralabe, provides background in the history of France and Switzerland, uncovers Abelard s relationships with his family, with the ruling house of Brittany and more, and most importantly draws together all that is known of Astralabe.