Overview

The Sibylline Books were a collection of Greek prophetic verses consulted by the Roman state at moments of crisis. By tradition the last king, Tarquinius Superbus, bought three surviving books from a Sibyl who had burned six of an original nine to force up the price. Kept in a stone chest beneath the Temple of Jupiter on the Capitol, they were opened only by decree of the Senate and only by a dedicated priesthood, and their advice repeatedly brought new gods and rites into Roman religion.

Roman legend holds that the Cumaean Sibyl offered nine books of oracular verse to King Tarquin, and, when he refused her price, burned three and offered the remaining six at the same price, then burned three more and offered the final three still at the original price; Tarquin, recognising what he faced, bought the last three books at the price first asked for all nine. The tradition of a sibyl demanding an escalating relative price for shrinking sets of books, familiar today chiefly through this Roman legend, has become a recurring reference point in later Western literature and rhetoric for a warning offer that grows costlier the longer it is refused, an afterlife in figurative language considerably more secure than the physical survival of the books themselves, none of which are known to exist today in any form.