The Constantinian dynasty is an informal name for the loosely related ruling families of the Roman Empire from the rise of Diocletian in 284 to the death of Julian in 363. It is named after its most famous member, Constantine I.

Stemmata

In italics the Augusti and the Augustae.

Descendants of Constantius Chlorus

• Constantius Chlorus
  1. From relationship between Constantius Chlorus and Helena
     • Constantine I
       1. From marriage between Constantine I and Minervina
          • Crispus
       2. From marriage between Constantine I and Fausta
          • Constantina, wife of Hannibalianus and Constantius Gallus
          • Constantine II
          • Constantius II
            1. No siblings from marriage between Constantius II and his first wife, daughter of Julius Constantius
            2. No siblings from marriage between Constantius II and Eusebia
            3. From marriage between Constantius II and Faustina
               • Flavia Maxima Faustina Constantia, wife of Gratian
          • Constans I
          • Helena, wife of Julian
  2. From marriage between Constantius Chlorus and Theodora
     • Flavius Dalmatius
       1. From marriage between Flavius Dalmatius and unknown wife
          • Flavius Dalmatius
          • Hannibalianus, husband of Constantina
     • Julius Constantius
       1. From marriage between Julius Constantius and Galla
          • son, died in the purges of 337^[1]
          • daughter, first wife of Constantius II
          • Constantius Gallus
            1. No siblings from marriage between Gallus and Constantina
       2. From marriage between Julius Constantius and Basilina
          • Julian
            1. No siblings from marriage between Julian and Helena, daughter of Constantine I
     • Hannibalianus (must have died before the imperial purges that occurred in 337 because he is not listed among its victims);
     • Anastasia;
     • Flavia Julia Constantia, wife of Licinius
     • Eutropia
       1. From marriage between Eutropia and Virius Nepotianus
          • Nepotianus

The Tetrarchs

• Diocletian
  1. From marriage between Diocletian and Prisca
     • Galeria Valeria, second wife of Galerius
• Maximian
  1. From marriage between Maximian and Eutropia
     • Theodora, wife of Constantius Chlorus (possibly daughter of Eutropia from a previous marriage)
     • Fausta, wife of Constantine I
     • Maxentius
       1. From marriage between Maxentius and Valeria Maximilla
          • Valerius Romulus
          • son
• Galerius
  1. From marriage between Galerius and unknown first wife
     • Valeria Maximilla, wife of Maxentius
  2. From marriage between Galerius and Valeria Galeria
     • Candidianus

• Diocletian: father-in-law and adoptive father of Galerius
• Maximian: father of Maxentius, adoptive father and stepfather-in-law of Constantius Chlorus, father-in-law of Constantine, stepgrandfather-in-law of Licinius
• Galerius: son-in-law and adopted son of Diocletian, uncle of Maximinus Daia, father-in-law of Maxentius
• Constantius Chlorus: father (and stepbrother-in-law) of Constantine, father-in-law of Licinius, adopted son and stepson-in-law of Maximian, adoptive brother and half-brother-in-law of Maxentius
• Maximinus Daia: nephew of Galerius
• Constantine: son (and stepbrother-in-law) of Constantius Chlorus, son-in-law of Maximian, brother-in-law of Maxentius, half-brother-in-law of Licinius
• Maxentius: son of Maximian, son-in-law of Galerius, adoptive brother and half-brother-in-law of Constantius Chlorus, brother-in-law of Constantine
• Licinius: son-in-law of Constantius Chlorus, half-brother-in-law of Constantine, half-nephew of Maxentius, stepgrandson-in-law of Maximian