The Emperors of Rome from Augustus to Constantine

(excluding minor children raised to the rank of Augustus who did not reign as Augustus in their own right)

Gordian II (co-emperor with Gordian I)  238

Pupienus and Balbinus  238

Gordian III (Caesar to Pupienus and Balbinus)  238

Gordian III  238-244

Philip  244-249

Decius  249-251

Gallus  251-253

Aemilianus  253

Valerian  253-260

Gallienus (as co-emperor with Valerian)  253-260

(as sole emperor)  260-268i

Claudius II  268-270

Vaballathus  269-271ii

Aurelian  270-275

Tacitus  275-276

Probus  276-282

Carus  282-283

Carinus  283-285

Numerian (co-emperor with Carinus)  283-284

Diocletian  284-305iii

Maximian (as Caesar)  285-286

(as Augustus)  286-305

Constantius I (as Caesar)  293-305

Galerius (as Caesar)  293-305

Constantius I (as Augustus)  305-306

Galerius (as Augustus)  305-311iv

Severus (as Caesar)  305-306

Maximin Daia (as Caesar)  305-310

Constantine (as Caesar)  306-308

Severus (as Augustus)  306-307

Maximin Daia (as Augustus)  310-313

Licinius (as Augustus)  308-324

Constantine (as Augustus)  308-337

Crispus (son of Constantine Augustus)

(as Caesar)  317-326

Licinius (son of Licinius Augustus) (as Caesar)  317-324

Constantine (son of Constantine Augustus) (as Caesar) 317-337 Constantius II (son of Constantine Augustus) (as Caesar) 324-337 Constans (son of Constantine Augustus) (as Caesar) 333-337

Dalmatius (nephew of Constantine Augustus) (as Caesar) 335-337

I

Ii

Iii

From 260-274 large portions of the empire to the west and north of the Alps were subject to a breakaway regime consisting of Postumus (260-269), Marius (269), Victorinus (269271), and Tetricus (271-274). Two other individuals, Laelianus (269) and Domitianus (271?) also claimed authority in this part of the empire, but Laelianus was killed by Postumus and actual evidence for Domitianus is presently limited to two coins and a passing reference in two texts, both of which claim that he rebelled against Aurelian, which may imply that his ‘‘reign’’ should be dated to 274 rather than 271.

Only in the eastern provinces.

From 286-296 portions of the western provinces were controlled by Carausius (286-293) and Allectus (293-296; Britain only).

Maxentius claimed the title Augustus in Italy from 306-312, he was not recognized as a member of the official college of Augusti.

Map 1 Provinces of the Roman Empire at the death of Trajan (ad 117)