Papal Oath

While a papal oath can be any oath taken by a pope, such as that which Pope Leo III took on 23 December 800 at a council held in Rome in the presence of Charlemagne declaring himself innocent of the charges brought against him, the term is used in particular for the "Papal Oath" (see text below) that some Traditionalist Catholics say was taken by the popes of the Catholic Church, starting with Pope Saint Agatho, who was elected on 27 June 678. They claim that over 180 popes, down to and including Pope Paul VI, swore this oath during their papal coronations. Pope John Paul I, Pope John Paul II, Pope Benedict XVI, and Pope Francis who had no coronation ceremonies, clearly did not take the oath, and some Traditionalists interpret this fact negatively, even to the point of declaring them to be false popes (see sedevacantism).

They claim that by this oath the popes swore never to innovate or change anything that has been handed down to them. Some of them confuse the alleged oath with the oath against modernism that Pope Pius X mandated for those taking up certain offices in the Church.

There is no evidence that any pope took such an oath during his coronation ceremony.

The "Papal Oath" they speak of appears to be loosely based on the text of the profession of faith, addressed to Saint Peter, included, as part of another document, in the Liber Diurnus Romanorum Pontificum, a collection of formularies for correspondence or decrees, some of which may even date from before the time of Pope Gregory I (590-604), while others may be of the time of the three existing manuscripts, and so of the 8th or 9th century.

While the collection was used in the papal chancery until the 11th century, the content of the document that contains the profession of faith shows that this formulary can have been used only at some time or times in the short period between the election of Pope Conon (686-687) and that of Pope Zachary (741-752); and the profession of faith speaks of the Third Council of Constantinople (680-681) as having been held recently ("nuper"), making the beginning of that period the most likely.

The profession of faith explicitly speaks of Pope Agatho (678-681) as already dead.