Story

Persecution, lapse, and schism

What the Roman state did, and what Christians did to each other afterward.

Step 1
Local, then imperial
For a long time persecution was local: Polycarp in Smyrna, the Lyon martyrs, Justin in Rome. Decius in 250 and Valerian soon after demanded sacrifices across the empire. Diocletian's persecution, from 303, was the most systematic in the East.
Polycarp of Smyrna Justin Cyprian of Carthage Smyrna Lyon Rome Carthage Catalog pg-77576 Move the map here
Step 2
The lapsed
When persecution eased, churches fought about people who had sacrificed. Cyprian wanted bishop-led penance. Novatian wanted lasting exclusion. The same wound opened again after Diocletian.
Cyprian of Carthage Novatian Meletius of Lycopolis Carthage Rome Alexandria Ancyra Move the map here
Step 3
Donatus and Caecilian
In Africa the fight became a lasting schism over Caecilian's ordination. Constantine and the council of Arles sided with Caecilian. Donatist churches remained numerous. Augustine was still arguing with them a century later.
Donatus Caecilian of Carthage Constantine I Augustine of Hippo Carthage Arles Hippo Regius Arles Move the map here

Local, then imperial