Before the day is done, we may have a new pope, and a new name to add to the Eucharistic Prayer at Mass.
The Holy See’s news site offers this interesting history of why popes have traditionally chosen new names:
The first act of the new Pope, immediately after accepting his canonical election as Supreme Pontiff and before fulfilling other obligations, is the choice of his name. This name is announced by the Cardinal Protodeacon after the famous formula “Habemus Papam”, followed by the Pope’s baptismal name in Latin.
According to a longstanding tradition, this name differs from the baptismal name—a choice that follows the precedent set by the first Pope, Saint Peter, whose birth name was Simon.
This custom emerged as early as the first millennium of Christianity to signify that the election to the Petrine See is akin to a second birth. In the early centuries of Christianity many Popes changed their names because their original names were of pagan origin.
However, not all Popes followed this practice. Out of the 266 Popes in history (267 including the next one), only 129 have chosen a new name.
This tradition became standard practice starting in 955 with Pope John XII, and has continued to this day, with the exceptions of Adrian VI (1522-1523) and Marcellus II (1555). For some Popes, the new name was actually their third name in life, as they came from religious orders.
As for the choice of the name, many often choose the same name of their immediate or recent predecessor out of respect, admiration, or recognition, which also signals the desire to follow in their footsteps and continue the most relevant pontificates.
Others choose a different name from that of their immediate predecessor, sometimes signifying a commitment to innovation and change. This was epitomized by Pope Francis, the first Pope in history to take the name of the Saint of Assisi.
In the history of the Papacy, the most commonly used name has been John, first chosen in 523 by Saint John I, Pope and martyr. The last Pope to choose this name was Italian Angelo Giuseppe Roncalli, elected Pope John XXIII in 1958, who was proclaimed Saint by Pope Francis in 2014.
Other frequently used names include Gregory, in honour of Pope Gregory I, commonly known as Saint Gregory the Great (590-604), which was last used by Gregory XVI in 1831, and Benedict which was chosen sixteen times, including by Joseph Ratzinger in 2005.
