Quindecimviri Sacris Faciundis
The Quindecimviri Sacris Faciundis were a college of fifteen priests in ancient Rome responsible for guarding and interpreting the Sibylline Books, a collection of prophecies and oracles. They were also responsible for overseeing the worship of foreign gods introduced to Rome and responding to divine advice and omens.
Originally, these duties were performed by the duumviri, two patrician officials. However, the number of priests was increased to ten in 367 BC by the Licinian-Sextian Law, which also mandated that half of the priests be plebeian.
Membership in the Quindecimviri was initially through co-option, meaning existing members selected new members. However, the Lex Domitia later changed this to an election process involving the voting tribes.
Digital Maps of the Ancient World 