For the earlier period their authorities were state and family records - above all, the annales maximi (or annales pontificum), the official chronicle of Rome, in which the notable occurrences of each year from the foundation of the city were set down by the pontifex maximus.
He prohibited heathen worship at Rome; refused to wear the insignia of the pontifex maximus as unbefitting a Christian;.
Cicero states that from the earliest period down to the pontificate of Publius Mucius Scaevola (c. 131 B.C.), it was usual for the pontifex maximus to record on a white tablet (album), which was exhibited in an open place at his house, so that the people might read it, first, the name of the consuls and other magistrates, and then the noteworthy events that had occurred during the year (per singulos dies, as Servius says).
Ancus Marcius is merely a duplicate of Numa, as is shown by his second name, Numa Marcius, the confidant and pontifex of Numa, being no other than Numa Pompilius himself, represented as priest.
The identification with Ancus is shown by the legend which makes the latter a bridge-builder (pontifex), the constructor of the first wooden bridge over the Tiber.