Imperial Colleges AD193-455
Although some emperors reigned alone or at least recognized no colleagues, any emperor with colleagues would usually issue laws or pronouncements in the name of the whole college, not just himself alone. The list given here is an attempt to show not simply reigns of emperors, but the continuing change and evolution of the imperial colleges. Exactness, however, is not possible. Even where diurnal dates are known for accession or death, it is a guess as to how fast such knowledge would reach other colleagues to allow for headings to pronouncements to be altered. For practical purposes, however, the colleges are presumed to change instantly. In the case of the third century in particular, however, exact days or even months are often lacking. The colleges given below are usually those of ‘legitimate’ emperors, and generally ignore usurpers, although some overlapping colleges show the claims of rival emperors. In some cases, even emperors, who recognized each other, constituted the imperial college in a different order or with differing members, altering such as relations between them warmed or cooled. It is, therefore, not possible in every case to be certain what college would have headed each pronouncement (supposing date and issuer to be sufficiently firm), and every conceivable imperial college is not listed. Generally, this is not a problem. Those periods with the most complex or uncertain arrays of imperial colleges are generally those with few or even no laws. Thus the period between the deaths of Constantius I and Maximinus Daza (306-313), or the periods of Decius and Gallus (249-253) and Claudius II to Carinus (268-285) simply have too few laws at the most chronologically difficult times to cause many problems.
31/12/192-28/03/193 | Imp. Pertinax A |
28/03/193-01/06/193 | Imp. Julianus A |
01/06/193-195 | Imp. Seuerus A |
195-28/01/198 | Imp. Seuerus A et Antoninus C |
28/01/198-Oct./Nov. 210 | Impp. Seuerus et Antoninus AA et Geta C |
Oct./Nov. 210-04/02/211 | Imppp. Seuerus Antoninus et Geta AAA |
04/02/211-26/12/211 | Impp. Antoninus et Geta AA |
26/12/211-Apr. 217 | Imp. Antoninus A |
Apr. 217-June 218 | Imp. Macrinus A |
May 218-26/06/221 | Imp. Antoninus A |
26/06/221-12/03/222 | Imp. Antoninus A et Alexander C |
12/03/222-mid.Mar. 235 | Imp. Alexander A |
mid.Mar. 235-Jan./Apr. 236 | Imp. Maximinus A |
Jan./Apr. 236-early June 238 | Imp. Maximinus A et Maximus C |
mid.Mar. 238-late Apr. 238 | Impp. Gordianus et Gordianus AA |
late Apr. 238-early Aug. 238 | Impp. Balbinus et Maximus AA et Gordianus C |
early Aug. 238-Feb. 244 | Imp. Gordianus A |
Feb. 244-mid.Aug. 244 | Imp. Philippus A |
mid.Aug. 244-July 247 | Imp. Philippus A et Philippus C |
July 247-Sep. 249 | Impp. Philippus et Philippus AA |
Sep. 249-early Sep. 250 | Imp. Decius A |
early Sep. 250-May 251 | Imp. Decius A et Decius et Quintus CC |
May 251-June 251 | Impp. Decius et Decius AA et Quintus C |
June 251-July 251 | Impp. Quintus et Gallus AA et Volusianus C |
July/Aug. 251 | Imp. Gallus A et Volusianus C |
July/Aug. 251-July/Aug. 253 | Impp. Gallus et Volusianus AA |
late July 253-mid.Sep. 253 | Imp. Aemilianus A |
mid.Sep. 253-Sep. 256 | Impp. Valerianus et Gallienus AA |
Sep. 256-summer 258 | Impp. Valerianus et Gallienus AA et Valerianus C |
summer 258-June 260 | Impp. Valerianus et Gallienus AA et Valerianus C |
June 260-autumn 260 | Imp. Gallienus A et Valerianus C |
autumn 260-early Sep. 268 | Imp. Gallienus A |
early Sep. 268-mid.Aug. 270 | Imp. Claudius A |
late Aug. 270-mid.Sep. 270 | Imp. Quintillus A |
late Aug. 270-Sep./Dec. 275 | Imp. Aurelianus A |
Sep./Dec. 275-June 276 | Imp. Tacitus A |
June 276-Aug. 276 | Imp. Florianus A |
June 276-Sep./Dec. 282 | Imp. Probus A |
Sep./Dec. 282-spring 283 | Imp. Carus A et Carinus et Numerianus CC |
spring 283-July 283 | Impp. Carus et Carinus AA et Numerianus C |
July 283-Nov. 284 | Impp. Carinus et Numerianus AA |
Nov. 284-spring 285 | Imp. Carinus A |
20/11/284-spring 285 | Imp. Diocletianus A |
spring 285-01/04/286 | Imp. Diocletianus A et Maximianus C |
01/04/286-01/03/293 | Impp. Diocletianus et Maximianus AA |
01/03/293-01/05/305 | Impp. Diocletianus et Maximianus AA et Constantius et Maximianus CC |
01/05/305-25/07/306 | Impp. Constantius et Maximianus AA et Seuerus et Maximinus CC |
July 306-spring 307 | Impp. Maximianus et Seuerus AA et Maximinus et Constantinus CC |
spring 307-11/11/308 | Impp. Maximianus A et Maximinus C |
11/11/308-May 310 | Impp. Maximianus et Licinius AA et Maximinus et Constantinus CC |
May 310-late 310 | Impppp. Maximianus Licinius Maximinus et Constantinus AAAA |
late 310-early May 311 | Impppp. Maximianus Maximinus Constantinus et Licinius AAAA |
early May 311-Oct. 312 | Imppp. Maximinus Constantinus et Licinius AAA |
Oct. 312-Apr. 313 | Imppp. Constantinus Maximinus et Licinius AAA |
Apr. 313-01/03/317 | Impp. Constantinus et Licinius AA |
01/03/317-19/09/324 | Impp. Constantinus et Licinius AA et Crispus Licinius et Constantinus CCC |
19/09/324-08/11/324 | Imp. Constantinus A et Crispus et Constantinus CC |
08/11/324- May 326 | Imp. Constantinus A et Crispus Constantinus et Constantius CCC |
May 326-25/12/333 | Imp. Constantinus A et Constantinus et Constantius CC |
25/12/333-18/09/335 | Imp. Constantinus A et Constantinus Constantius et Constans CCC |
18/09/335-22/05/337 | Imp. Constantinus A et Constantinus Constantius Constans et Dalmatius CCCC |
22/05/337-09/09/337 | [Imp. Constantinus A et] Constantinus Constantius et Constans [et Dalmatius C]CCC |
09/09/337- Spring 340 | Imppp. Constantinus Constantius et Constans AAA |
Spring 340- Jan. 350 | Impp. Constantius et Constans AA |
Jan. 350-15/03/351 | Imp. Constantius A |
15/03/351-354 | Imp. Constantius A et Constantius C |
354-06/11/355 | Imp. Constantius A |
06/11/355-03/11/361 | Imp. Constantius A et Iulianus C |
[Feb. 360-03/11/361] | [Impp. Constantius et Iulianus AA] |
04/11/361-26/06/363 | Imp. Iulianus A |
27/06/363-17/02/364 | Imp. Iouianus A |
26/02/364-28/03/364 | Imp. Valentinianus A |
28/03/364-24/08/367 | Impp. Valentinianus et Valens AA |
24/08/367-17/11/375 | Imppp. Valentinianus Valens et Gratianus AAA |
17/11/375-22/11/375 | Impp. Valens et Gratianus AA |
22/11/375-09/08/378 | Imppp. Valens Gratianus et Valentinianus AAA |
09/08/378-19/01/379 | Impp. Gratianus et Valentinianus AA |
19/01/379-19/01/383 | Imppp. Gratianus Valentinianus et Theodosius AAA |
19/01/383-25/08/383 | Impppp. Gratianus Valentinianus Theodosius et Arcadius AAAA |
25/08/383-15/05/392 | Imppp. Valentinianus Theodosius et Arcadius AAA |
[384-387] | [Impppp. Valentinianus Theodosius Arcadius et Maximus AAAA] |
15/05/392-23/01/393 | Impp. Theodosius et Arcadius AA |
23/01/393-17/01/395 | Imppp. Theodosius Arcadius et Honorius AAA |
17/01/395-10/01/402 | Impp. Arcadius et Honorius AA |
10/01/402-01/05/408 | Imppp. Arcadius Honorius et Theodosius AAA |
01/05/408-15/08/423 | Impp. Honorius et Theodosius AA |
[08/02/421-02/09/421] | [Imppp. Honorius Theodosius et Constantius AAA] |
15/08/423-23/10/424 | Imp. Theodosius A |
23/10/424-23/10/425 | Imp. Theodosius A et Valentinianus C |
23/10/425-28/07/450 | Impp. Theodosius et Valentinianus AA |
28/07/450-25/08/450 | Imp. Valentinianus A |
25/08/450-16/03/455 | Impp. Valentinianus et Marcianus AA |