Internet History Sourcebooks Project
Fordham University: Medieval Sourcebook: Edicts of Toleration
This site contains information on two important religious edicts given by Roman emperors relating to Christianity and its role as a persecuted religion in ancient Rome.
PBS
Pbs: Chronology of Early Christianity
A detailed timeline on the early history of the religion from the time of Julius Caesar (44 B.C.E.) to 327 C.E. and the death of Constantine.
Other
The Latter Rain: Constantine
This extensive resource documents the life of Constantine. Article is written from a Christian perspective. It goes into depth about the freedom he gave to Christians, and the effects of the Edict of Milan.