This map was drawn by Adolf Harnack and has been digitized from Adolf Harnack, The Mission and Expansion of Christianity in the First Three Centuries, translated and edited by James Moffatt, second edition, vol. 2 (New York: G. P. Putnam's Sons, 1908).
Because of the time elapsed since the copyright date, these images are now in the public domain.
Only those towns are marked on the map in which it can be proved that Christian communities existed prior to 180 A.D.
Places where Christian communities are demonstrable or certain prior to Trajan are underlined.
Places which are not quite certain as towns with a Christian community prior to 180 A. D. are put within brackets.
The shading indicates that while Christians certainly existed in the district in question, the names of the cities where they stayed have not been preserved. Except in the case of Egypt, the shading is omitted whenever even one town in the province in question can be shown to have had a Christian church.
The principal Roman roads are marked by double lines.