_Causes of the Apostasy.--External Causes, Continued_.
Pagan persecution.--Roman opposition to Christianity, explanation
of.--Number of persecutions by the Romans.--Persecution under
Nero.--Under Domitian.--Under Trajan.--Under Marcus Aurelius.--Later
persecutions.--Persecutions under Diocletian.--Extent of the
Diocletian persecution.--Diocletian boast that Christianity was
extinct.--The Church taken under state protection by Constantine the
Great.