Estimates of dating based on the language and other textual evidence have ranged from AD 130[2] (which would make it one of the earliest examples of apologetic literature), to the general era of Melito of Sardis, Athenagoras of Athens, and Tatian.
"[4] Scholars have suggested individuals who could be the addressee of the Letter to Diognetus, one implausible (one of the emperor Marcus Aurelius' tutors),[5] the other quite possible (an Alexandrian procurator, Tiberios Claudios Diognetos, c.200).
At least one of these two was a member of the city council, a status that would make the term κράτιστος, used of the addressee of the Letter to Diognetus, very appropriate.
Unfortunately the original was subsequently destroyed in a fire during the Franco-Prussian War in 1870,[10] but numerous transcriptions of the letter survive today.
It has been suggested that the Epistle should be identified with the Apology of Quadratus of Athens, mentioned by Eusebius in his Church History,[11] but this is disputed among scholars (see below).
[12] In 1947 Paulus Andriessen suggested that the Epistle to Diognetus is to be identified with the Apology of Quadratus of Athens, mentioned by Eusebius in his Church History.