Eusebius of Caesarea, a careful if not inerrant historian, reports that during Trajan's reign (98-117), indeed according to his Chronicle precisely in the year 107, the Church of the great city of Antioch-on-the-Orontes in Syria suffered persecution and lost its bishop Ignatius. Letters under Ignatius' name survive in three editions, a middle recension of seven letters, an expanded edition with six additional letters stressing the primacy of the see of Antioch, and an abbreviated edition of three letters extant in a Syriac version. Most of the letters insist on the authority of bishops. Fourth-century squabbles between bishops competing for power made the documents popular in that age, as Eusebius expressly remarked (HE 3. 36. 2). The texts would have been especially congenial to a bishop of Antioch in the 370s and 380s, at a time when he had to assert his position in competition with three rivals in a divided city. The recension known to Eusebius had seven letters in which Ignatius, under arrest, communicated with churches in Asia Minor at Philadelphia, Smyrna, Tralles, Magnesia, and Ephesus. In addition the Roman church was addressed without mention of a bishop, and also Polycarp bishop of Smyrna. This collection of seven letters was known to Irenaeus and Origen and is therefore earlier than 160-70. It is a disputed question whether they are as early as Eusebius says. A collection of Ignatius' letters was known to Polycarp, his own letter to the Philippians being a covering letter for the set. That suggests that the letters should be assigned, if not necessarily to the first decade of the second century, at least not later than the third or fourth decade. Accordingly the question of dating turns on whether enough is known of the development of the second-century Church for a confident judgement to be possible that the seven letters are somehow anachronistic in the first or second decade, but entirely possible ten or twenty years later.
Dispute on this last question cannot readily be settled. At least it is safe to say that not enough is known about the Church early in the second century