Albert H. Buck, The growth of medicine from the earliest times to about 1800 (1917)
“ Aëtius.—Aëtius was a native of Amida, in Mesopotamia, and he lived during the early part of the sixth century A. D., under the Emperor Justinian I. He studied medicine at Alexandria and then settled in Constantinople, where he was appointed to the double office of private physician to the emperor and commanding officer of his body-guard (Comes obsequii) ,—an arrangement which made it practicable for the emperor to have his physician near his person on all possible occasions. ”
