The Great Persecution and What It Left Behind

The edicts began in 303 and escalated. First the destruction of church buildings and the surrender of scriptures, then the arrest of clergy, then their release on condition of sacrifice, and finally, in 304, a general order that everybody sacrifice. Enforcement varied enormously by region and by the appetite of the local ruler, which is why the persecution was severe in the east and in Africa and slight in the west. Galerius called it off in 311 in an edict that effectively admitted it had not worked, and Constantine reversed the policy outright soon afterwards.

Two consequences outlasted the empire in the west. The first is a quarrel. Clergy who had handed over the scriptures were called traditores, and in North Africa the question of whether sacraments administered by such men were valid produced the Donatist schism, which was still running a century later and drew Augustine into some of his most consequential writing about what a church is. The second is a calendar. The Coptic Orthodox Church counts its years as the Era of the Martyrs, and the epoch it dates from is the accession of Diocletian. A church that survived him keeps his name at the head of every date it writes, which is a stranger memorial than anything he built.