Illuminatus was likely martyred during the Reign of Diocletian. The Diocletianic Era was the unusual practice of reckoning time from the start of the reign of the bitterly anti-Christian Emperor Diocletian (r. 284–305). This is in recognition of the severe persecution of the Church under Diocletian and his colleagues in rule, Maximian (r. 286-305) and Galerius (r. 305-311), although the formal universal oppression did not commence until 303, the so-called Great Oppression. Another colleague, or junior emperor, Caesar Constantius I Chlorus (r. 293-306), was conspicuous for his leniency toward Christians.