This is the second volume of a 3-volume set entitled "Early History of the Christian Church: From its Foundation to the End of the Fifth Century." (NY 1909-1924). Originally published in French as “Histoire ancienne l’Eglisse” (Paris, 1905-1910) . Fully edited with linked footnotes. This second volume covers the Fourth Century: The Great Persecution, Constantine, Eusebius, Athanasius, Julian, Basil, Ambrose, etc. Duchesne’s classic work served as the standard introduction to the early church for many years. Orthodox Catholic historian Warren H. Carroll, the late founder of Christendom College, lauded the work as “excellent and thorough,” noting: “Though privately an early modernist, Duchesne, in this classic did not challenge orthodox doctrine nor engage in indiscriminate debunking.”