From Peter to Francis: How the pope chooses their name

As the world waits for the conclave at the Vatican to elect a new pontiff, another question remains at the back of everyone’s minds: What will his new name be?

Before he stepped out of the balcony of St. Peter’s Basilica in 2013 as Pope Francis in tribute to the saint of Assisi, the late pontiff was known as Cardinal Jorge Mario Bergoglio.

That’s because for nearly 1,500 years, the leader of the Catholic Church has opted to change his name following his election, a tradition born out of humility and commitment to his flock.

While every pope is free to choose their own name, many opt to either honor their predecessor or pick from one of the favorites that have come up throughout the centuries.

Whoever is elected during Wednesday’s conclave will have a wide range of options, but there are some unspoken rules and restrictions.

How do popes pick their papal names?

There is no written set of rules dictating how the pope chooses his name, with the elected pontiff generally given free rein on the matter.

Many popes choose the name of their predecessor, which is why several are repeated in the long list of pontiffs, such as 16 Pope Benedicts and even more Pope Johns.

Francis was among the leaders who opted to name himself after a saint, his entry being the first in centuries to add a new name that had not previously appeared on the papal registry.

When did popes start picking names?

Experts generally agree that the first documented instance of a pope changing his name came in the year 553, with the election of Pope John II.

It’s believed that the pontiff, who bore the name Mercurio after the Roman god of the planet Mercury, felt it was inappropriate to keep the name of another deity while heading the Catholic Church.

Instead, Mercurio opted to humble himself and take the name John, after Pope John I, starting the new tradition that would not fully catch on until another 1,000 years.

What’s the unwritten rule?

While the pontiff can name himself whatever he wishes, there is one name all the popes have avoided thus far: Peter.

In the history of the church, there has only been one Pope Peter, the saint and first pontiff charged with leading the original followers of Jesus.

While it isn’t strictly forbidden, it would likely be seen as sacrilege for a new pope to name himself after such a central figure in the Catholic Church.

How many Pope Johns are there really?

In the long list of popes who have served the Catholic Church, there is one name that comes up more than any other, John.

How many Johns there have been, however, is a bit confusing given the existence of Pope John XXIII despite the name only appearing 21 times in the official papal registry.

The first anomaly comes with Pope John XVI, who is not officially recognized in the Vatican’s registry over his role as an anti-pope, a man claiming to be the leader of the church in direct opposition to the one elected by cardinals.

The second comes from the fact that there was never any Pope John XX, with scholars believing a recording error occurred in the 200 years between the 19th and 21st John.