Pontifex maximus

The highest sacerdotal authority of ancient Rome. The title appears to mean "Bridge builder", although it has always been unclear why, and many proposals have been put forward as an explanation, none of them convincing.

The office came into its own with the abolition of the monarchy, when the sacral powers previously vested in the king were transferred to it. The Pontifex "Maximus = greatest" was the president of a college of nine, later fifteen, pontifices, co-opted for life.

Tertullian first applied the term to Pope Callixtus I, although Pope Gregory I was the first to employ it in any formal sense. Pontifex was apparently a word in common currency in early Christianity to denote a bishop.