Originally, the practice of keeping a fire was central to domestic well-being: for the Romans, maintaining a constant fire was often easier than relighting one regularly. The cult of Vesta grew out of this practice; the position of the Vestal Virgins, who tended the sacred fire, was originally held by the Roman king's daughters, who, like other young Roman girls, were responsible for tending the house's fire. The fire in the temple of Vesta, who was herself always personified as living flame (Ovid, Fasti, vi), was thus the hearth fire of the city. As the extinction of a hearth fire was a misfortune for a family, so the extinction of Vesta's flame was thought to portend national disaster for Rome—which explains the severe punishment (usually death) of Vestals who allowed the fire to go out.
The Vestal Virgins (they originally numbered two, but were later increased to four and eventually six) were selected by lot and served for thirty years, tending the holy fire and performing other rituals connected to domestic life—among them were the ritual sweeping of the temple on June 15 and the preparation of foods for certain festivals. By analogy, they also tended the life and soul of the city and of the body politic through the sacred fire of Vesta, which was renewed every year on the Kalends of March.
The sacred fire burned in Vesta's circular temple, which was built in pre-republican times, in the Roman Forum below the Aventine Hill. Other sacred objects were stored within the temple, including the Palladium (a statue of Pallas Athena) supposed to have been brought by Aeneas from Troy. The temple burned completely on at least four occasions and caught fire on two others. The current temple (somewhat restored in the 20th century) dates from 191 AD, when Julia Domna, wife of the emperor Septimius Severus, ordered a thorough rebuilding. The rites of Vesta ended in 394, when the fire was extinguished and the Vestal Virgins disbanded by order of Theodosius I.