The Sibyl was a priestess directly inspired by the deity, consecrated to the god Apollo. She was portrayed as a young and beautiful girl or as a graceless woman, but predisposed to the art of divination . She had the gift of foresight , that is, to see an event in advance and to indicate its positive or negative outcome, reporting its enigmatic verdicts. Her words,  which coul not be easily interpreted, represented the most complex and feared response by the Greek-Roman populations, who attributed to the Sibyl a strong decision-making power, her word was sacred and inviolable.

She loved to retire to caves and caverns dug into the rock , away from the clamor. Her underground dwelling was an environment full of spiritual suggestions, with torches arranged in every corner that illuminated the entrance to visitors, allowing them to reach the heart of the cave. Before prophesying her response, she performed a ritual, walking along the three large tanks in the cave and immersing herself in the waters. 

Once the ceremony was completed , he sat on the high throne and questioned the oracle; the final verdict was issued and reported on palm leaves , then moved by the wind stirred up by Apollo . The oracles , written in Greek on the leaves, made up the famous Sibylline Books which represented the highest level of knowledge of the Ancients collected in volumes , which foretold future events.

In the legend of the Cumaean Sybil, it is said that the god Apollo fell in love with the beautiful girl at first sight and promised her that he would fulfill her every wish.
Sibilla took a handful of sand from the beach and asked Apollo to let her live as many years as the grains she had in her hand. The God satisfied her but the girl forgot to specify that she wanted to live in eternal youth. His home was Cuma , chosen as a place of meditation to be able to officiate the art of divination . She aged more and more year by year. In order to preserve her, Apollo placed her in a cage inside the cave, until only her voice remained. Legend has it that only a handful of her native earth would break the spell that would allow her to die in peace.

The Cumaean Sibyl was the most influential figure in ancient history thanks to Virgil’s Aeneid , drawing the attention of the Roman emperors and noble patricians, who reached the Acropolis of Cuma to question its oracles . Cuma became the religious nucleus of the entire Roman Empire , a destination for pilgrimages and ancient glories.

However, only a few priestly members linked to the cult of Apollo could access the Sibylline and they were jealously guarded in the temple of Jupiter Capitolinus . The introduction and use of the Sibylline books in Rome is the oldest proof of the Hellenic influence which penetrated Rome from southern Italy and precisely from Cuma . These volumes burned in the tragic fire of the Campidoglio in 83 BC. The books were subsequently reassembled, together with all the oracles present in Magna Graecia and placed by the Emperor Augustus himself , in the temple of Apollo on the Palatine Hill ; guarded until the IV they were destroyed by the Roman General Stilicone . According to another legend, the Sibylline Books were presented to Tarquinius Priscus by the Sibyl herself, asking for a fee for the nine volumes . This one rejected the offer as expensive; she then burned the first three books and then three more , until the king, considering their preciousness, bought the last three for the price of nine .

The Sibylline verses had the characteristic of being acrostics both for mnemonic reasons and for a guarantee of inalterability. Their tenor was deliberately obscure and generic, such that it could be adapted to the most varied circumstances, especially on the occasion of public natural or social calamities, so that it could suggest a way to appease the gods, thus restoring the pax deorum.