Secret prophecies: the mysterious Sibylline Books that controlled Ancient Rome's destiny

The Sibylline Books were stored as scrolls rather than bound volumes and probably contained unclear prophetic verses that were written in Greek hexameter.

Their presence in Rome was connected, according to tradition, to a legend from the reign of Tarquinius Superbus, who was the city’s final king and who ruled from approximately 534 to 509 BCE.

As the story, which was later recorded by Livy and Dionysius of Halicarnassus, related, a veiled woman approached the king and offered to sell him nine books filled with divine knowledge.

After he refused her price, she burnt three of them in full view, then offered the remaining six for the same sum.

When he rejected her again, she destroyed three more and insisted on the original amount for the final three.

Only after he had watched six books burn did Tarquinius reportedly give in. Once the deal was completed, the woman disappeared. 

According to Roman tradition, the woman was none other than the Sibyl of Cumae, a prophetess with the gift of foresight who had lived near the Greek colony of Cumae in southern Italy.

Once they had been acquired, the remaining scrolls were reportedly placed under tight guard in the Temple of Jupiter Optimus Maximus on the Capitoline Hill, where only appointed priests had access.

Known first as the duoviri sacris faciundis and later expanded to the decemviri under the Licinian-Sextian reforms in 367 BCE, the priestly college eventually grew to fifteen members, the quindecimviri sacris faciundis, likely during Sulla's reforms in the 1st century BCE.

This group alone held the power to consult the texts and give their explanations to the Senate.

The Senate then decided how the state would act. Eventually, plebeians were permitted to join their ranks, which apparently reflected the growing political inclusivity of the Republic. 

The verses within the Sibylline Books generally remained hidden from the general population, which was unable to read or interpret them.

They had probably been written in ancient Greek and had been composed in a poetic form that avoided direct predictions.

The books generally did not present clear outcomes, but instead, typically offered instructions for religious rites that needed to be performed in response to specific signs or public emergencies.

These verses had likely been inscribed on parchment or papyrus in scroll format and had been stored in round containers to preserve them. 

For this reason, the priests rarely quoted the books directly. They instead usually delivered a set of ritual recommendations to the Senate, which might include building a new temple, adopting the worship of a foreign deity, or holding sacrifices and festivals intended to calm the gods' anger.

According to Roman belief, disasters such as plagues and natural omens were taken to indicate a breakdown in the pax deorum, the harmony between gods and mortals, and the Sibylline Books were used as the required action to restore balance. 

As a result, the instructions found within the scrolls were rarely specific about dates or names.

Rather than predicting events in detail, the verses showed a way of thinking that held that correct religious practice and civic order were inseparable, and where divine punishment followed any failure to keep the proper forms of worship.

In this sense, the books appeared to act less as tools of prophecy and more as a religious guide to government that influenced how Rome understood its responsibilities to the gods. 

The books were treated as sacred instruments, consulted only under exceptional situations, which occurred when Rome faced threats too unusual or severe for ordinary religious responses.

Plagues, floods, eclipses, earthquakes, or sudden omens such as statues weeping blood or animals speaking Latin were all considered valid reasons to turn to the Sibylline verses.

The belief that the gods could communicate their displeasure through such events demanded a response grounded in religious tradition. 

For example, in 399 BCE, a severe plague swept across the city, so the Senate was unable to calm public fear through traditional means and ordered the quindecimviri to consult the scrolls.

After reading the verses, the priests reportedly recommended the introduction of the cult of Apollo Medicus, who was a healing deity from the Greek world.

Although some traditions trace Apollo's worship in Rome to earlier influences, this was the first official start of his cult with a dedicated temple approved by the Senate.

This action was likely the first formal recognition of Apollo in Rome and showed how foreign cults could enter Roman religion when endorsed by the books. 

In another case, during the Samnite Wars in 293 BCE, a second outbreak of disease led the priests to call for the importation of Asclepius, the Greek god of medicine.

Roman envoys travelled to Epidaurus, retrieved a statue and a sacred serpent, and brought the cult to the Tiber Island, where a temple was established.

As a result, the Sibylline Books acted as protection for the city by requiring the rituals that the gods demanded.

During the political disorder following the assassination of Julius Caesar in 44 BCE, multiple signs and public anxiety prompted renewed consultation of the books, though little is known about the specific rites prescribed. 

One of the most important uses of the Sibylline Books occurred during the Second Punic War.

After Hannibal’s crossing of the Alps and his early victories in Italy, the Roman people became increasingly desperate.

In 216 BCE, strange events, such as a hermaphrodite birth, an ox that spoke, and showers of stones, convinced the Senate that the gods were angry.

A consultation of the books followed, which led to a startling recommendation: four human sacrifices were required.

The Senate, usually resistant to such practices, buried two Greeks and two Gauls alive in the Forum Boarium.

Although this act went against traditional Roman values, the Senate obeyed, believing that divine instruction overruled cultural objections. 

Another famous case took place in 204 BCE, when the war with Carthage reached a turning point.

The Senate was urged by omens and public unrest and ordered the Sibylline Books to be opened.

The priests reported that Rome must bring the sacred image of the Magna Mater, the Great Mother of the Gods, from Asia Minor.

So, the Senate dispatched an embassy to Pessinus, received the sacred black stone that represented the goddess, and welcomed it to Rome with great ceremony.

The arrival of the Magna Mater was seen as a religious turning point. Shortly afterward, Scipio Africanus defeated Hannibal at Zama. 

Roman leaders in later years also relied on the books to justify major religious events.

For instance, during his reign, Augustus revived the Ludi Saeculares in 17 BCE, claiming that ancient Sibylline prophecies supported the celebration.

He invoked the authority of the scrolls and combined prophecy with politics. He presented his rule as the fulfilment of divine plans.

Although the books bore similarity to Greek oracles such as the one at Delphi, their restricted use by Roman officials and focus on state rites made them a uniquely Roman institution. 

In 83 BCE, a fire destroyed the Temple of Jupiter Optimus Maximus, and ancient sources suggest that the original Sibylline Books perished in the flames.

The loss created a religious problem because without the scrolls Rome lacked a crucial source of divine guidance.

As a solution, the Senate instructed the quindecimviri to collect new verses from across the Greek world.

Priests are said to have travelled to cities such as Ilium, Samos, Erythrae, and Cumae to collect oracular texts that were claimed to come from genuine Sibyls. 

When they returned to Rome, the priests checked each verse, discarded those thought false, and compiled a new official collection, so this new version, which was then stored in the rebuilt temple, resumed its place in Roman religious life.

Still, doubts persisted. Many Romans believed that the original power of the books may have been lost forever.

Even though the institution survived, the sense of mystery and divine power had lessened. 

Eventually, their influence gradually decreased as Christian influence increased and the state viewed such pagan texts with doubt.

The books' association with foreign gods and mysterious rites no longer aligned with the empire’s new religious identity.

Some Christian authors dismissed them as dangerous relics of idolatry, even as fake Christian Sibylline prophecies began to circulate in later centuries. 

Around 405 CE, the last known destruction took place. Accounts from the time apparently described Stilicho's efforts to eliminate pagan religious power that might challenge Christian rule.

Under his orders, the remaining Sibylline Books were reportedly burned. Some scholars suggested Stilicho aimed to remove pagan sources of religious power that might challenge imperial rule.

So ended the most famous oracles of the Roman world. The Christian state rejected them as dangerous relics of paganism, and no attempt was made to preserve or hide them. 

Because no citizen had read the texts in centuries, only literary references and scattered summaries probably gave later generations any sense of what they might have contained.

What once guided Rome’s most sacred decisions had disappeared from the world.

For over six hundred years, the Sibylline Books had long been said to have expressed the gods' will, and their loss likely brought about the final silence of the old gods in a city that had once lived by their word.