The rite of the coronation of a Pope seems to date from the time when the western Patriarchs began to make definite claims to a temporal sovereignty. The rite does not appear till the ninth century, but probably existed in some form for a century before this date. Already in the Liber Pontificalis[146] it is stated that Pope Constantine wore during his visit to Constantinople a head-dress peculiar to the Roman Pope. This is called the Camelaucus, and is evidently the original form of the Tiara. In the ‘Donation of Constantine’ of the pseudo-Isidorian decretals[147], in which the Papal temporal claims were first formulated, Constantine the Great is said to have granted to the Pope the sovereignty of the West and to have bestowed on him and his successors a special royal diadem, which is described as ‘phrigium candido nitore splendidum,’ evidently the camelaucus under a different name, a closed head-dress something of the shape of a Phrygian cap, and probably related to the Crown of the eastern bishop. Although the ‘Donation’ does not mention any ceremony of coronation, perhaps one is implied by this claim that the Papal head-gear is a temporal crown.

In the ninth century the rite existed and is described in Mabillon’s Ordo Romanus IX[148]. The ceremony never became so elaborate as a royal coronation. The Pope elect, who must not be a bishop, enters St Peter’s during the Introit Elegit te Dominus. His consecration as a bishop then takes place. Three special prayers are said for him by three different bishops[149]. The archdeacon then invests him with the Pallium (i.e. the ecclesiastical vestment), and he is enthroned on a specially prepared throne. The new Pope celebrates Mass himself, and after the Gloria in excelsis the Laudes are sung. When Mass is over he is enthroned upon the apostolic throne. Then he proceeds to the steps at the west end of St Peter’s, and after the acclamation thrice repeated Domnus Leo Papa quem Sanctus Petrus elegit in sua sede multis annis sedere, he is crowned with the Regnum or Tiara, which is described as being white and shaped like a helmet. He then mounts a horse and returns to his palace amid the acclamations of the people.

The rite seems to have changed very little in the process of time. Ordo XII[150], which is of the twelfth century, gives a little more information. On the Sunday after his election the Pope proceeds to St Peter’s, and there before the high altar is consecrated bishop by the Bishop of Ostia and other bishops. The consecration over, the Cardinal Deacon of St Laurence places the Pallium on the high altar, whence the Archdeacon takes it and invests the Pope in it saying: Accipe pallium, plenitudinem scilicet pontificalis officii, ad honorem omnipotentis Dei et gloriosissimae Virginis eius genitricis et beatorum apostolorum Petri et Pauli et sanctas Romanae ecclesiae. The Pope then celebrates Mass. After the Laudes, the Epistle and Gospel are read both in Latin and Greek. Mass being finished, the Pope returns to his palace with the Tiara on his head, but there is no indication of any ceremonial crowning having taken place.

Ordo XIV[151] of the fourteenth century is fuller. The Pope is now generally already a bishop at the time of his election. The newly-elected Pope proceeds to St Peter’s and begins Mass. After the Confiteor he takes his seat before a faldstool between his throne and the altar, and there prayers are said for him by the Cardinal Bishops of Albano, Porto and Ostia. First the Bishop of Albano says the prayer: Deus qui adesse non dedignaris ubicumque devota mente invocaris, adesto quaesumus invocationibus nostris et huic famulo tuo N. quem ad culmen apostolicum commune iudicium tuae plebis elegit ubertatem supernae benedictionis infunde, ut sentiat se tuo munere ad hunc apicem pervenisse. Next the Bishop of Porto says the second prayer, Supplicationibus, Omnipotens Deus, effectum consuetae pietatis impende, et gratia Spiritus Sancti hunc famulum tuum N. perfunde; ut qui in capite ecclesiarum nostrae servitutis mysterio constituitur, tuae virtutis soliditate roboretur. The Bishop of Ostia says the third prayer, Deus qui Apostolum tuum Petrum inter caeteros coapostolos primatum tenere voluisti, eique universae Christianitatis molem superimposuisti; respice propitius quaesumus hunc famulum tuum N. quem de humili cathedra violenter sublimatum in thronum eiusdem apostolorum principis sublimamus: ut sicut profectibus tantae dignitatis augetur, ita virtutum meritis cumuletur; quatenus ecclesiasticae universitatis onus, te adiuvante, digne ferat, et a te qui es beatitudo tuorum meritam vicem recipiat.

The Pope now receives the reverence of the Cardinals and Prelates present, who kiss his foot and face. He then goes to the altar where the Cardinal Deacon of St Laurence invests him in the Pallium, with the form already given. He then goes up to the altar and censes it, and returns to his seat, where he receives again the reverence of the Cardinals and Prelates. He then begins Gloria in excelsis, and says Pax vobis and the Collect for the day and says secretly for himself another prayer[152]. Then he returns to his seat and the Laudes are sung:

Exaudi Christe.

Domino nostro N. a Deo decreto summo Pontifici et universali Papae vita.

Salvator mundi. ?. Tu illum adiuva (ter).

Sancta Maria. ?. Tu illum adiuva (bis).

Sancte Michael. ?. Tu illum adiuva, etc., etc.

After the Laudes have been sung, Mass proceeds, the Epistle and Gospel being read in Greek as well as in Latin. At the conclusion of the Mass the Pope goes in procession to the staging erected on the steps at the west end of the Basilica of St Peter. There the ‘Prior diaconorum cardinalium’ removes his mitre, and sets the Tiara or Regnum, which is by this time adorned with three crowns, on his head, the people crying Kyrie eleison. The Pope then blesses the people and returns on horseback to the Lateran.

This represents the final stage of the rite, except for one picturesque feature added in the fifteenth or sixteenth century. As the Pope leaves the chapel of St Gregory for his consecration, the Ceremoniarius lights a piece of tow on the end of a reed which flares for a moment and then goes out, saying, Pater Sancte, sic transit gloria mundi[153].

It will be seen that the Papal rite is very simple. It is clear that the ceremonies, with the Laudes and other acclamations[154], owe much to the Imperial coronation rite of early times, but have undergone very little change or development since the ninth century.