Roman family tree

This is the only tree on the site that has to be read twice — once as a genealogy of gods, and once as a document of Roman politics. The divine descent lines on it were largely imported from Greece by writers who wanted Latin gods to have stories. The lines that ran from a goddess down through Troy to a family living in Rome in the first century BCE were the ones Romans actually argued about.

The imported half

Once Roman writers equated their gods with Greek ones, the Greek genealogies came with them: Jupiter as son of Saturn, Juno as sister and wife, Neptune and Pluto as brothers, Minerva from Jupiter's head, Mars and Vulcan as Juno's sons, Venus, Apollo, Diana, Mercury and Ceres in their inherited positions.

The diagram draws these because Roman literature uses them constantly, and marks them as what they are: an adopted structure, not an Italic inheritance. Latin cult offers very little independent evidence for any of it. Nobody in Rome sacrificed on the strength of a belief that Vulcan was Juno's son.

The half that is genuinely Roman

Several important Roman gods have no parents on this tree, and that is not a gap in the evidence. They never had any.

• Janus, of doorways and beginnings, invoked first in prayers before Jupiter, with no Greek counterpart and no family.
• Vesta, the state hearth, whose fire is the goddess and who has no image and no offspring.
• Terminus, the boundary stone, who cannot be moved and cannot be related to anything.
• Quirinus, third member of the oldest triad, whose original character had become obscure even to antiquarian writers of the first century BCE.
• The numina, powers of extremely specific functions, who have no persons at all and therefore no descent.

Where Greek religion generated relationships, Roman religion generated offices. A tree is the wrong instrument for a great deal of it, and the diagram says so rather than filling the space.

The line that mattered

The genealogy Romans took seriously ran from Venus to Aeneas, from Aeneas to Iulus (also called Ascanius), and from Iulus to the gens Iulia — which is to say to Julius Caesar and, through adoption, to Augustus. Virgil's Aeneid exists in large part to establish it, and Augustus built the temple of Venus Genetrix, Venus the ancestress, to make the claim in stone.

That is a family tree functioning as a constitutional document. It connects Rome to the Homeric world, gives the ruling family divine descent, and makes the Aeneid's hero the ancestor of the man who commissioned the poem.

Beside it runs the second foundation line: Mars fathering the twins Romulus and Remus on Rhea Silvia, a Vestal of the Alban royal house descended from Aeneas. The two stories were stitched together by pushing the Alban king-list between them to bridge four centuries, and the join is visible.

Where the sources disagree

• Whether these gods have parents at all. The archaic Roman evidence gives no genealogy for Janus, Vesta, Terminus, Faunus, Fortuna or Bellona; the imported Greek scheme supplies one for a few of them. The diagram marks imported descents with a broken line.
• Romulus and Quirinus. After his death Romulus was said to have been taken up and identified with Quirinus, which merges a founder with an archaic god. Whether the identification is ancient or a late rationalisation is disputed.
• Aeneas' son. Ascanius and Iulus are one figure in Virgil, and other traditions make Iulus a separate son, precisely because a Roman family's claim depended on which.
• The Etruscan layer. Tinia, Uni and Menrva stand behind Jupiter, Juno and Minerva independently of any Greek route. Where a relationship is likelier to have come through Etruria than through Greece, the note says so.

Reading the diagram

Solid lines are relationships attested in Latin sources in their own right. Broken lines are Greek genealogies adopted into Latin literature, which is most of the divine half. The mortal descent from Venus through Aeneas is drawn as a continuous line into historical families, because that is exactly how Romans drew it — and this is the only tree here that ends in people whose dates are known and whose tombs existed.

The emperors join the diagram

One further extension has no parallel on any other tree here. From Augustus onward, a dead emperor could be voted divine by the senate, which meant that a living man's father might be a god by legislation. Divus Iulius, Divus Augustus and their successors enter the divine register by a vote, with temples, priests and festivals attached, and their descendants inherit accordingly.

The diagram shows these as a distinct kind of edge, because deification by decree is neither descent nor cult in the ordinary sense — it is a political act using religious vocabulary, and Romans themselves joked about it. Vespasian's reported deathbed remark that he supposed he was becoming a god is the sharpest surviving comment on the institution.

What the shape shows

Put the two halves side by side and the difference is stark. The imported section is dense, incestuous and full of stories. The native section is a scatter of unconnected offices with no relationships at all. That contrast is the best single argument against the idea that Roman gods are Greek gods with new names, and it is worked through properly on the Greek and Roman pantheon comparison and in the Roman tradition hub.