The Age of Accession of Roman Emperors

Bust of Gratian against black background.
Gratian, the youngest Roman Emperor.

Print Collector / Getty Images

Looking at the callous behavior of several of the young Roman emperors it's hard not to wonder if too much power was thrust upon immature shoulders. The following table shows the approximate age of accession of the Roman emperors. For those emperors with no birth information, the approximate date of accession and the birth year are marked with question marks.

Unless otherwise indicated, all dates are A.D.

The Age of Accession of Roman Emperors

Mean average age = 41.3
Oldest = 79 Gordian I
Youngest = 8 Gratian

Emperor Birth Year Reign Approximate Age at Accession
Augustus 63 B.C. 27 B.C.- 14 A.D. 36
Tiberius 42 B.C. A.D. 14-37 56
Caligula A.D. 12 37-41 25
Claudius 10 B.C. 41-54 51
Nero A.D. 37 54-68 17
Galba 3 B.C. 68-69 65
Otho A.D. 32 69 37
Vitellius 15 69 54
Vespasian 9 69-79 60
Titus 30 79-81 49
Domitian 51 81-96 30
Nerva 30 96-98 66
Trajan 53 98-117 45
Hadrian 76 117-138 41
Antoninus Pius 86 138-161 52
Marcus Aurelius 121 161-180 40
Lucius Verus 130 161-169 31
Commodus 161 180-192 19
Pertinax 126 192-193 66
Didius Julianus 137 193 56
Septimius Severus 145 193-211 48
Pescennius Niger c. 135-40 193-194 55
Clodius Albinus c. 150 193-197 43
Antoninus - Caracalla 188 211-217 23
Geta 189 211 22
Macrinus c. 165 217-218 52
Diadumenianus (son of Macrinus, birth unknown) 218 ?
Elagabalus 204 218-22 14
Severus Alexander 208 222-235 14
Maximinus Thrax 173? 235-238 62
Gordian I 159 238 79
Gordian II 192 238 46
Balbinus 178 238 60
Pupienus 164 238 74
Gordian III 225 238-244 13
Philip the Arab ? 244 - 249 ?
Decius c. 199 249 - 251 50
Gallus 207 251 - 253 44
Valerian ? 253 - 260 ?
Gallienus 218 254 - 268 36
Claudius Gothicus 214? 268 - 270 54
Aurelian 214 270 - 275 56
Tacitus ? 275 - 276 ?
Probus 232 276 - 282 44
Carus 252 282 - 285 30
Carinus 252 282 - 285 30
Numerian ? 282 - 285 ?
Diocletian 243? 284 - 305 41
Maximian ? 286 - 305 ?
Constantius I Chlorus 250? 305 - 306 55
Galerius 260? 305 - 311 45
Licinius 250? 311 - 324 61
Constantine 280? 307 - 337 27
Constans I 320 337 - 350 17
Constantine II 316? 337 - 340 21
Constantius II 317 337 - 361 20
Julian 331 361 - 363 30
Jovian 331 363 - 364 32
Valens 328 364 - 368 36
Gratian 359 367 - 383 8
Theodosius 346 379 - 395 32

Sources