The first great Christian physician whose works meant much for his own time, and whose writings have become a classic in medicine, was Aetius Amidenus, that is, Aetius of Amida, who was born in the town of that name in Mesopotamia, on the upper Tigris (now Diarbekir), and who flourished about the middle of the sixth century. His medical studies, as he has told us himself, were made at Alexandria. After having attracted attention by his medical learning and skill, he became physician to one of the emperors at Byzantium, very probably Justinian, (527-565). He seems to have been succeeded in the special post that was created for him at court by Alexander of Tralles, the second of the great Christian physicians. There is no doubt that Aetius was a Christian, for he mentions Christian mysteries, and appeals to the name of the Saviour and the martyrs. He was evidently a man of wide reading, for he quotes from practically every important medical writer before his time. Indeed, he is most valuable for the history of medicine, because he gives us some idea of the mode of treatment of various subjects by predecessors whose fame we know, but none of whose works have come to us. His official career and the patronage of the Emperor, the breadth of his scholarship, and the thoroughly practical character of his teaching, show how medical science and medical art were being developed and encouraged at this time. Aetius' work that is preserved for us is known in medical literature as his sixteen books on medical practice. In most of the manuscript it is divided into four Tetrabibloi, or four book parts, each of which consists of four sections called Logoi in Greek, Sermones in Latin. This work embraces all the departments of medicine, and has a considerable portion devoted to surgery, but most of the important operations and the chapters on fractures and dislocations are lacking. Aetius himself announces that he had prepared a special work on surgery, but this is lost. Doubtless the important chapters that we have noted as lacking in his work would be found in this. He is much richer in pathology than most of the older writers, at least of the Christian era; for instance, Gurlt says that he treats this feature of the subject much more extensively even than Paulus AEginetus, but most of his work is devoted to therapeutics.