This article records tradition as it has been passed down and reported. Its sources are not yet part of the atlas's verified catalogue.
Christianity is suppressed across the Roman Empire through two empire wide persecutions a century and a half apart, the best documented episodes of organized violence against the faith under pagan Rome. In January 250 CE the emperor Decius issued an edict requiring every inhabitant of the empire to sacrifice to the Roman gods and obtain a certificate, a libellus, proving compliance, refusal brought imprisonment, torture or death, and Decius's own death in battle the following year ended the edict's enforcement.
The second and larger persecution came in February 303 CE, when the emperor Diocletian, urged on by his junior colleague Galerius, opened what later Christian writers called the Great Persecution. Four escalating edicts ordered the destruction of church buildings and scriptures, the imprisonment of clergy and eventually universal sacrifice on pain of death, enforced harshest and longest in the eastern provinces under Galerius and Maximinus Daia, and lighter and shorter in the west under Constantius.
What this changed for Christianity's spread was a temporary but severe check on the faith's public life across the empire, one that ended only with Galerius's own Edict of Toleration, issued from Nicomedia in April 311 CE as he lay dying, two years before Constantine and Licinius met at Milan and set the empire on a different course toward the faith altogether.