 The books "(libri)" and commentaries "(commentarii)" of the College of Pontiffs and of the augurs contained religious procedures, prayers, and rulings and opinions on points of religious law.Although at least some of this archived material was available for consultation by the Roman senate, it was often "occultum genus litterarum", an arcane form of literature to which by definition only priests had access.Prophecies pertaining to world history and to Rome's destiny turn up fortuitously at critical junctures in history, discovered suddenly in the nebulous Sibylline books, which Tarquin the Proud (according to legend) purchased in the late 6th century BC from the Cumaean Sibyl.