born in 245, Diocletian assumed power as Roman emperor in 284; an astute administrator, he decided that the key to governing the vast Roman empire was to divide it; he ruled with Maximian in 285, and then added two more "junior emperors" in 293, one of whom was Constantius, the father of Constantine; in 305 he abdicated and retired; Diocletian is probably best known for his ten-year persecution of the Christians, which made him the frequent villain in Christian literature in the Middle Ages; Diocletian died in 313.

An ancient Roman motif adopted by Palladio in the 16th century, this is a semicircular window divided into three parts by two wide uprights (mullions). Also called a "therm," it was most often seen on early 20th-century Classical Revival structures.

The 'Godless King' featured defeated on 11th Century icon from Sinai

Roman emperor 284-305. He wished to restore the old proud splendour and stability of the empire and to some extent succeeded - his reign was the first for over a century to last twenty years. He retired to be a vegetable grower in Croatia, his native country.

Roman emperor from 284 to 305 c.e.; restored later empire by improved administration and tax collection. (p. 259)

Gaius Aurelius Valerius Diocletianus (c. 245–c. 312), born Diocles (Greek Διοκλής) and known in English as Diocletian,The full name Diocletian is derived from the Greek díos kletos ("sky-called"). was Roman Emperor from November 20 284 to May 1 305.