The stemmata of imperial families and dynasties available at this site are listed below, along with a few notes of explanation. In general, these family trees are inclusive rather than exclusive; I have attempted to put as many emperors as possible into each stemma, even when the family links seem somewhat tenuous. Since new imperial families often attempted to promote their ties to the old, this can sometimes help in understanding the history, or at least the propaganda, of a period. To that end, even emperors whose link may result from nothing more than a liaison to some member of a dynasty (for which I use a symbol for correlation) are included. In some cases, a certain amount of conjecture is involved; the notes outline the source of the conjectures of others, and my own conjectures are clearly identified in the stemmata themselves. I do not identify conjectures generally accepted by scholars. On another point, the question of legitimacy is not always easy to solve in the case of such rulers as Maxentius, Vetranio and Magnus Maximus; I have generally taken refuge in the level of their acceptance by other emperors rather than their later reputation, but some scholars may dispute my conclusions. Corrections and other changes will be made as I become aware of the need for them, and I note as well that I have very little inclination to attempt the third century. The names of emperors are generally those by which they are typically known, though I have occasionally added real or assumed names in parentheses, particularly for the Severans, to show nomenclature or propaganda: even scholars might not always remember that (M. Julius) Gessius Alexianus Bassianus is Severus Alexander.

Files and Images

The stemmata are, in most cases, quite large, and viewers will not always be able to see an entire tree on the screen at one time without a monitor capable of displaying large images. The size of images and files are listed with the links below. Two conventions used here may be worth noting. (1) I use lines with arrows at each end to link marriages where the layout demands that two individuals cannot be located side by side; the line indicating offspring from a marriage displayed in this way sometimes begins from that line. (2) When lines need to cross each other, I use a red half-circle to simplify the intersection. In general, lines of descent need to be followed very carefully, since it is often impossible to keep generations and even all members of a family at the same level.


The text, the lines showing the links between individuals and some of the other material were prepared with a simple drawing programme, because text entry in particular is needlessly complicated in most high-end graphics programmes. After a stemma was complete, it was copied into a graphics programme, fitted with a background and other niceties and converted to a JPEG image.

Legitimate Use

These stemmata may be used by any amateur or professional student or teacher for any legitimate nonprofit educational purpose. Commercial use is specifically prohibited without the prior permission of the author. Any author who might wish to include a stemma or a portion of it in a published work must also obtain permission.

© J. Vanderspoel, Department of Greek, Latin and Ancient History, University of Calgary

The Julio-Claudians and Some Relatives 178K, 1152 x 720 pixels

All emperors from Augustus to Vitellius. Otho is included by virtue of his relationship with Poppaea.

The Flavian Emperors 35K, 560 x 434 pixels

The emperors from Vespasian to Domitian and some relatives.

Trajan, Hadrian and the Antonines 162K, 1075 x 815 pixels

Emperors from Nerva and Trajan to Commodus, as well as some of their relatives. For this document, several of the stemmata at the back of A.R. Birley's translation of the Historia Augusta, entitled Lives of the Later Caesars (Penguin), and his Marcus Aurelius have been collated into a single stemma. The series of stemmata in Birley's Marcus Aurelius are accompanied by notes on some of the relationships here.

The Severans 64K, 724 x 532 pixels

This stemma of the Severans accepts most of the conclusions of A.R. Birley, Septimius Severus. The African Emperor, and also found in his translation of the Historia Augusta, entitled Lives of the Later Caesars (Penguin). Note the hypotheses about the ancestry of Flavia Neratia Septimia Octavilla. Her grandmother must be Septimius Severus' sister, who, in Birley's view, possibly married a man named L. Flavius ? Aper, judging by her father's name (Neratia comes from her mother, presumably). The question is whether her father, L. Flavius Septimius Aper Octavianus and known to be the son of a Lucius, is the same person as L. Septimius Aper, consul in 207. This may seem unlikely: Septimius Severus gave his sister and her son a few honours, then sent them back to Africa, embarrassed because they spoke Latin so poorly, according to the Historia Augusta. On that basis, her son could hardly be the consul of 207, though the text may well be tendentious; Birley is not in favour of the identification. Another branch of the family had been at Rome longer than the branch to which Septimius Severus belonged. P. Septimius Aper was consul in 153, and the consul of 207 could be his grandson, hardly his son. Another possibility is available: if a son of the consul of 153 married Septimius Severus' sister (their respective fathers were cousins, and while an uncle might not marry a niece, the kinship here would be acceptable), Aper would be part of a son's name. The praenomen Lucius, his own (and his father's), is not otherwise known in the Roman branch of the family (equally true if the consul of 207 is a grandson of the consul of 207 by another line of descent), but is known in the collateral branch. Finally, the name Flavius does not appear in any part of the family and must have entered by marriage. If, however, the consul of 153 had married a Flavia, his son might bear that name as well (note Caracalla, originally named Septimius Bassianus, from his father and his maternal grandfather). His name would then be L. Flavius Septimius Aper and a son by Septimia Octavilla could bear the name L. Flavius Septimius Aper Octavianus. All this remains very hypothetical, though there is an economy of assumptions in this solution. The stemma shows all the possibilities in a different colour, with the regular black indicating what is certain. Note that not all the possibilities shown can be operative at the same time.

The Tetrarchs and their Descendants 95K, 1000 x 600 pixels

The emperors from Diocletian through the descendants of Constantine to Julian; a few usurpers are missing. Two emperors, Severus and Jovian, cannot, on the basis of current knowledge, be linked to the stemma, and Vetranio can only be included because of a relationship of some type, but not marriage and probably not a sexual liaison, with Constantina. Though Severus is said to have been a friend of Galerius, it is presumably too much to hope that evidence of a shared liaison during their military days will come to light. He and Jovian are included for completeness at appropriate points, however. Parts of this stemma, in origin an attempt to find the family connections of Julius Julianus and now amplified, depend on conjectures discussed and/or proposed by T.D. Barnes, The New Empire of Diocletian and Constantine (1982); I suggest some modifications and add a few conjectures of my own, which receive full discussion in a treatment of Julius Julianus.

The Dynasty of Theodosius 106K, 1100 x 765 pixels

Emperors from Valentinian and Valens to Marcian. Originally designed to illuminate a study of the names in the Theodosian dynasty and its marriage links with barbarians, discussion of the conjectures made here is now part of a larger project on Stilicho's role in maintaining the dynasty after the death of Theodosius. A few usurpers do not appear. The conjectures of J.R. Martindale, "Note on the Consuls of 381 and 382," Historia 16 (1987), 254-256, on the maternal relatives of Serena are included. On the basis of naming patterns, I suggest a few which have not always appeared previously. Magnus Maximus' link to the family, I propose, is the result of an uncle's marriage to Theodosius' sister.

From Diocletian to Marcian 164K, 1044 x 732 pixels

All emperors from Diocletian to Marcian and thus a combination of the two previous items; see the notes there. Gratian's marriage to the daughter of Constantius and the probability that Justina, wife of first Magnentius, then Valentinian, was a granddaughter of Crispus, eldest son of Constantine (see the book by T.D. Barnes noted above), offer the necessary links between the stemmata. In this version, as compared to the previous two together, the names and lines have been pushed closer together and some of them have been moved around a bit; though the file size is larger, the image is slightly smaller than the previous one (the text size is the same) and the lines of descent are a little more difficult to follow. Note, however, that the emperors, but not necessarily Caesars, are pretty much in chronological order from top to bottom; it was too difficult to place all the usurpers in their proper place, though most are, but rest assured that the legitimate emperors always managed to do so.


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Last modified February 2014