The Byzantine world underwent a remarkable recovery of intellectual energy in the period following the recovery of Constantinople in 1261. The reaction of the emperors and their entourage of well-educated high officials to their political disasters was a deliberate reivial of the glories of ancient Greek culture. The main subject of this book is the preservation and dissemination by this learned elite of such ancient literature, philosophy and science as still survived then, the development of editorial techniques which resulted in more complete and less corrupt texts, and their improvement buy the addition of commentaries and other innovations.