traditionally the Sabine king who ruled with Romulus (Romulus and Remus), the founder of Rome. It is unlikely that either Titus Tatius or Romulus was a historical personage. According to the legend, the conflict between the Romans and the Sabines began when Romulus invited the Sabines to a festival and abducted their women. Titus Tatius then seized Rome's Capitoline Hill by bribing Tarpeia, daughter of the commander of the Roman guard. In the ensuing battle, fought in the valley between the Capitoline and Palatine hills, the Sabine women rushed into the fray and stopped the fighting. A formal treaty was drawn up uniting the Romans and Sabines under a dual kingship of Titus Tatius and Romulus. The community continued to be called Rome, but, as a concession to the Sabines, its citizens were known as Quirites (from Cures, the principal town of the Sabines). The dual kingship survived for only a few years before Titus Tatius was killed by a mob.

The Romans read much back into the legend of Titus Tatius. In addition to viewing the reign of Titus Tatius and Romulus as the prototype of their own dual magistracies, they found in Titus the eponym of both the Titienses (one of the three original Roman tribes) and the religious brotherhood known as the sodales Titii.

Titus Tatius is credited by tradition with establishing altars to many deities (probably Sabine) at Rome, among them Ops, Flora, Veiovis, Saturn, Sol, Luna, Vulcan, Summanus, Larunda, Terminus, Quirinus, Vertumnus, the Lares, Lucina, and Diana.