Ioannes Tzetzes wrote to reassure the wife of the megas hetairarches that the city of Constantinople was very strong. He stressed the importance of its walls, and declared that the history of the city showed a succession of emperors who each contributed to the urban fabric and its protection. To judge from the letter, his correspondent was nervous about the approach of the armies of the Second Crusade, the circulation of gloomy prophecies and an ominous dream