When did the Pope start to use the ancient pagan title of “Pontifex Maximus”?

It is often stated online that the ancient title for the Roman high priest, “Pontifex Maximus”, was adopted by the Pope in the 4-5th centuries, as paganism disappeared.  The exact details are often vague, which should always raise suspicion.

In fact this does not seem to be true, and the title is only applied to the popes in the 15th century and later.  There has been quite a few articles in the literature on the subject.  It seems worth summarising the argument here.

The Greek word “ἀρχιερεύς” (arch-hiereus, chief priest) is used in the LXX, in Josephus, the Gospels and Acts, in many places for the chief priests or the high priest of the Jews, as this resource makes clear.   In Hebrews 2:17, Christ himself is called “our great high-priest”, using the same word.

But the word is also used in Greek inscriptions in the east of the Roman empire for priests of the imperial cult.   In fact in Rome itself, writing in Greek, Plutarch uses it to mean “pontifex” in the “Life of Numa”, chapter 9, explaining the origins of the office (online here):

Νομᾷ δὲ καὶ τὴν τῶν ἀρχιερέων, οὓς Ποντίφικας καλοῦσι

To Numa is also ascribed the institution of that order of high priests who are called Pontifices,

“Pontifex” also used in the Latin version of 1 Clement 40:5, 41:2, 43:4, where Christ is called “Pontifex”.  So we find early Christian Latin texts using the word “pontifex” to mean “bishop” – the Christian equivalent of “chief priest” – with no pagan meaning.  Kajanto’s excellent article (online here) gives many examples of the early Christian Latin use of “pontifex”, and he shows that it simply means “bishop”, citing the earliest use in the Collectio Avellana, letter 1, dating from ca. 370.  It is then widely used in Christian Latin with this meaning, although “episcopus” is always preferred.^[1].

So it is normal Latin, with no difference for pagan, Jewish, or Christian use, to use the Latin word “pontifex” to translate “chief priest” in the bible.  “Pontifex” has no pagan meaning, and simply means “priest” or “chief priest”, from which “bishop”.

The phrase “Pontifex Maximus” is another matter.  It does not appear in any of these sources.  There is indeed a corresponding Greek phrase for “pontifex maximus”.  It is ἀρχιερεύς μέγιστος (arch-hiereus megistos), which is used in at least one inscription to mean Pontifex Maximus, in Sylloge inscriptionum Graecarum 832. (See LSJ, via Logeion, here).

There are only three usages of Pontifex Maximus in antiquity to refer to anyone but a pagan.

1. Tertullian in De Pudicitia 215 uses the term to deride a bishop who had announced that adultery could be forgiven by filling in a form at the diocesan office.
2. Prosper Tiro in a 5^th century text uses the term for the Jewish High Priest, “Hebraeorum pontifex maximus”.
3. Isidore of Seville refers to the pope thus in Etymologies12:13, but it is probably a slip for pontifex summus.
4. It’s not much.  Here is what Isidore says:

13.  Pontifex princeps sacerdotum est, quasi via sequentium. Ipse et summus sacerdos, ipse pontifex maximus nuncupatur. Ipse enim efficit sacerdotes atque levitas: ipse omnes ordines ecclesiasticos disponit: ipse quod unusquisque facere debeat ostendit.

The ‘pontifex’ is the chief of priests, as if the word were ‘the way’ of his followers. And he is also named the ‘highest priest’ and the pontifex maximus, for he creates priests and levites (i.e. deacons); he himself disposes all the ecclesiastical orders; he indicates what each one should do.”

As Kajanto has observed, it is clear that the Christians actively avoided using “pontifex maximus”, preferring to use “summus pontifex” instead.

Inevitably there are many websites that have other ideas, and a range of popes are mentioned.  One site here states confidently that Pope Siricius did so, giving sources and referencing the Catholic Encyclopedia.  But if you check, online here, you find that the CE and the sources refer to the title of “papa”, not “pontifex maximus”.

There are many pieces of older academic literature which say that the title “pontifex maximus” came into use during the papacy of Pope Leo I (440-461). This includes the 2^nd edition of the Oxford Dictionary of the Christian Church, under “Pontifex Maximus” – but not the 3^rd edition where the bibliography includes Kajanto’s article.  I learn from Dijkstra and van Espelo, “Anchoring Pontifical Authority”, that a series of modern articles have rejected this view.^[2]

It seems that it is Boniface IX, who reigned from 1389-1404, who was the first pope on whose monuments the title appears.  According to Dijkstra and van Espelo, and R. Schieffer, “Der Papst als Pontifex Maximus”^[3] p.307, the evidence for this is a contemporary marble statue in the cloister of St Paul without the Walls in Rome, which shows the pope seated with an open book in his hands bearing the inscription “D. O. M. BONIFATIVS IX P. MAX. STIRPE THOMACELLVS GENERE CIBO”.

Here in fact is the statue of Boniface IX, ca. 1400.  Note that the pedestal text may not be contemporary.

The title is next attested under Martin V (1417-31) in a dedication inscription from the church of S. Lorenzo in Miranda in the forum.  There are some possible inscriptions from Eugenius IV (1431-47), and certainly more from Nicholas V (1447-1455).  Schieffer warns, however, that appearances of “P.M.” in the inscriptions on the tombs of popes before 1450 are probably later additions.  It is under Paul II (1464-71) that it becomes a standard part of “papal vocabulary”, according to Dijkstra and van Espelo.

There are uncertainties here.  Inscriptions can be amended.  Some of these items may have had “P.MAX” added later.  So it is not certain when the title was first used.  What does seem to be certain is that using “Pontifex Maximus” for the pope is an innovation of the 15^th century.  The inscriptions in which it appears use classical language, and are certainly influenced by the renaissance and a return to classical usages.

I was unable to find any serious discussion of literary and documentary evidence.  In 1981 Kajanto stated that the term “pontifex maximus” for the Pope first appeared in literary texts only after 1500.  He frankly confessed that this was based on “the inadequate resources for neo-Latin”.  Schieffer stated that it remained rare until after 1500, and even then, while it was applied to popes, it was not a title that the Popes used of themselves, in bulls and letters issued by the papal chancellery.  Possibly the conservatism of that department, and the literary forms used, is responsible for this.

In conclusion, there is no evidence whatever of the pope assuming the title formally in antiquity.

1. ^[1]I. Kajanto, “Pontifex Maximus as the title of the pope”, Arctos 15 (1981), 37-52;  p.39. Online here.↩
2. ^[2]E.g. R. Dijkstra and D. van Espelo, “Anchoring Pontifical Authority: A Reconsideration of the Papal Employment of the Title Pontifex Maximus”, Journal of Religious History 41 (2017), 312-325. Online at: https://doi.org/10.1111/1467-9809.12400.↩
3. ^[3]R. Schieffer, “Der Papst als Pontifex Maximus”, Zeitschrift der Savigny-Stiftung für Rechtsgeschichte 57 (1971): 300–309.  This reference via Dijkstra / van Espelo, p.320.↩