The Sibylline Books were a collection of oracular utterances, purchased from a sibyl by the last king of Rome, Tarquinius Superbus, and consulted at momentous crises through the history of the Republic and the Empire. Only fragments have survived, the rest being lost or deliberately destroyed.
According to the Roman tradition, the oldest collection of Sibylline books was attributed to the Hellespontine Sibyl and was preserved in the temple of Apollo at Gergis. The collection passed to Erythrae, where it became famous it found its way to Cumae and from Cumae to Rome. The Cumaean Sibyl offered to Tarquinius nine books of these prophecies; and as the king declined to purchase them, owing to the exorbitant price she demanded, she burned three and offered the remaining six to Tarquinius at the same stiff price, which he again refused, whereupon she burned three more and repeated her offer. Tarquinius then relented and purchased the last three at the full original price and had them preserved in a vault beneath the Capitoline temple of Jupiter.
The Roman Senate kept tight control over the Sibylline Books; Sibylline Books were entrusted to the care of two patricians; after 367 BC ten custodians were appointed, subsequently their number was increased to fifteen. They had the responsibility of keeping the books in safety and secrecy. These officials, at the command of the Senate, consulted the Sibylline Books in order to discover not exact predictions of definite future events in the form of prophecy but the religious observances necessary to avert extraordinary calamities and to expiate ominous prodigies (comets and earthquakes, showers of stones, plague, and the like). It was only the rites of expiation prescribed by the Sibylline Books, according to the interpretation of the oracle that were communicated to the public, and not the oracles themselves, which left ample opportunity for abuses.
In particular, the keepers of the Sibylline Books had the superintendence of the worship of Apollo, of the “Great Mother” Cybele or Magna Mater, and of Ceres, which had been introduced upon recommendations as interpreted from the Sibylline Books. The Sibylline Books motivated the construction of eight temples in ancient Rome, aside from those cults that have been interpreted as mediated by the Sibylline Books simply by the Greek nature of the deity. Thus, one important effect of the Sibylline Books was their influence on applying Greek cult practice and Greek conceptions of deities to indigenous Roman religion.
The books were kept in the Temple of Jupiter on the Capitol, and, when the temple burned in 83 BC, they were lost. The Roman Senate sent envoys in 76 BC to replace them with a collection of similar oracular sayings, in particular collected from Ilium, Erythrae, Samos, Sicily, and Africa. This new Sibylline collection was deposited in the restored temple, together with similar sayings of native origin. Private ownership of such works being declared illicit, and to be evaluated by the Quindecemviri, who then sorted them, retaining only those that appeared true to them. From the Capitol they were transferred by Augustus in 12 BC, to the temple of Apollo Patrous, after they had been examined and copied; there they remained until about AD 405. The general Flavius Stilicho (died AD 408) burned them, as they were being used to attack his government. Some genuine Sibylline verses are preserved in the Book of Marvels or Memorabilia of Phlegon of Tralles (2nd century AD). They report the birth of an androgyne, and prescribe a long list of rituals and offerings to the gods.