Tarquin the Proud was king a strange thing happened at Rome. One day an unknown woman came to the king, bearing in her arms nine books, which she offered to sell to him at a certain price. She told him that they contained the prophecies of the Sibyl of Cumć, and that from them might be learned the destiny of Rome and the way to carry out this destiny.

But the price she asked for her books seemed to the king exorbitant, and he refused to buy them, whereupon the woman went away from the palace and burned three of the volumes. She then returned with six only and offered them to the king, but demanded the same price for the six as she had before done for the nine. King Tarquin heard this demand with laughter and mockery, and again refused to buy. The woman once more left the palace, and burned three more of the books.

To the king's astonishment his strange visitor soon returned, bearing the three books that remained. On being asked their price, she named the same sum as she had demanded for the six and the nine. This was ceasing to be matter for mockery. There might be some important mystery concealed behind this strange demand. The king sent for the augurs of the court, told them what had happened, and asked what he should do. They told him that he had done very wrong. In refusing the books he had refused a gift of the gods. By all means he must buy the books that were left. He bought them, therefore, at the Sibyl's price. As for the woman, she was never seen again.

The books were placed in a chest of stone, and kept underground in the great temple which his father had begun on the Capitoline Hill, and which he had completed. Two men were appointed to guard them, who were called the two men of the sacred books; and no treasure could have been kept with more care and devotion than these mysterious rolls.

The temple in which these books were kept was the grandest edifice Rome had yet known. When Tarquin proposed to build it he found the chosen site already occupied by many holy places, sacred to the gods of the Sabines, the first dwellers on the Capitoline Hill. The augurs consulted the gods to see if these holy places could safely be removed, to make room for the new temple. The answer came that they might take away all except the holy places of the god of Youth and of Terminus, the god of boundaries. This was accounted a happy augury, for it seemed to mean that the city should always retain its youth and that no enemy should remove its boundaries. And when the foundations of the temple were dug a human head was found, which was held to be a sign that the Capitoline Hill should be the head of all the earth. So a great temple was built, and consecrated to Jupiter and to Juno and to Minerva, the greatest of the Etruscan gods. This edifice, afterwards known as the Capitol, was the most sacred and revered edifice of later Rome.

In the vaults of this temple the sacred books of the Sibyl were sedulously kept, and here they were consulted from time to time, as occasions arose in the history of the city when divine guidance seemed necessary. None of the people were permitted to gaze within the sacred cell in which they lay. Only the augurs consulted them, and the word of the augurs had to be taken for what they revealed. It may be that the augurs themselves invented all that they told, for the books at length perished in the flames, and no man knows what secret lore they really contained.

It was during the wars of Sulla and Marius (83 ) that this disaster occurred. The Capitol was burned, and with it those famous oracles, which had so long directed the counsels of the nation. Their loss threw Rome into the deepest consternation, the loss of the Capitol itself seeming small beside that of these famous scrolls.

To replace them as far as possible, the senate sent embassadors to the various temples of Italy, Greece, and Asia Minor, within which were Sibyls, or oracle-speaking priestesses. These collected such oracles referring to Rome as they could find, about one thousand lines in all, and brought them to Rome, where they were placed in the same locality in the new Capitol that they had occupied in the old.

These oracles do not appear to have predicted future events, but were consulted to discover the religious observances necessary to avert great calamities and to expiate prodigies. During the reign of Augustus they were removed to the Temple of Apollo on the Palatine Hill, and all the false Sibylline leaves which were extant were collected and burned. They remained here until shortly after the year 400 , When they were publicly burned by Stilicho, a famous general of Christian Rome, as impious documents of heathen times.