We have fairly little information about Theodorus Priscianus. He himself in the preface to his Physica describes himself as a student of Vindicianus; the latter taught and practised medicine, was translator of Greek works into Latin as well as proconsul of Africa at the beginning of Theodosius' reign. On the basis of these data, we can assume that Theodorus lived around the 4th-5th century AD, and linguistic concordances with Caelius Aurelianus and Cassius Felix can corroborate the hypothesis of his origin and education in Africa. The manuscripts that hand down his works mention his profession as a physician: Theodorus Priscianus archiater; the hypothesis put forward, according to which he was the physician of the emperor Gratianus, remains doubtful, since the name archiater in the heading of his work could be understood as civic archiater. 

Of Theodorus we have a treatise on pathology in 3 books entitled Euporiston, and a fragment of another treatise on magical natural remedies, the Physica. [Giuseppe Trovato]