23. Temporary Repose. a.d. 260-303. (Chapter 2: Persecution of Christianity and Christian Martyrdom.) (History of the Christian Church) (Schaff, Philip)

Gallienus (260-268) gave peace to the church once more, and even acknowledged Christianity as a religio licita. And this calm continued forty years; for the edict of persecution, issued by the energetic and warlike Aurelian (270-275), was rendered void by his assassination; and the six emperors who rapidly followed, from 275 to 284, let the Christians alone.

The persecutions under Carus, Numerianus and Carinus from 284 to 285 are not historical, but legendary.

During this long season of peace the church rose rapidly in numbers and outward prosperity. Large and even splendid houses of worship were erected in the chief cities, and provided with collections of sacred books and vessels of gold and silver for the administration of the sacraments. But in the same proportion discipline relaxed, quarrels, intrigues, and factions increased, and worldliness poured in like a flood.

Hence a new trial was a necessary and wholesome process of purification.