When a new pope is elected by the College of Cardinals, one of his first acts is to choose a new name. But why do popes change their names?

While not all Catholic religious leaders take new names, the tradition is common in certain religious orders and deeply ingrained in the papacy. Accepting a new name marks a new stage in life — an entry into a different role and community. According to the Sioux Falls Bishop’s Bulletin, the tradition dates back to 533, when a man named Mercurius was elected pope. Given the pagan connotations of his name (Mercury was a Roman god), he chose to become Pope John II, naming himself after a martyred predecessor.

The practice became widespread by the 10th century. The last pope to keep his birth name was Marcellus II, elected in 1555.

When Jorge Bergoglio was elected pope in 2013, he became the first pope from the Americas, the first Jesuit pope, and the first to take the name Francis. He later explained his decision during a meeting with journalists. According to the Catholic Herald, Brazilian Cardinal Claudio Hummes told him, “Don’t forget the poor,” just after his election. Pope Francis recalled, “That struck me… Immediately I thought of St. Francis of Assisi. Francis was a man of peace, a man of poverty, a man who loved and protected creation.”

Some papal names have been used often — especially John, which 23 popes have taken, making it the most common. Benedict (16 times) and Gregory (also 16) are next. These names often reflect spiritual role models or continuity with predecessors.

Some names, however, have only been used once — like Lando, Hilarius, and Romanus. And the first pope, St. Peter, remains the only one to use that name.

A pope’s chosen name is one of his first public messages. In the modern era, Pope John Paul II chose his name to honor John Paul I and the two popes who led the Second Vatican Council. Pope Benedict XVI pointed to Benedict XV, a World War I-era peacemaker, and St. Benedict, founder of Western monasticism.

If a future pope chooses Francis II, it may signal a continuation of the previous pope’s focus on outreach to the marginalized. A name like Benedict XVII or John Paul III might suggest a return to doctrinal clarity, Many believe Leo XIV is more plausible, referencing both Leo I (“the Great”) and Leo XIII, known for Catholic social teaching.

But Could a pope choose a brand-new name? Yes — and Pope Francis did exactly that. He was the first in over 1,100 years to choose a previously unused name.

There are plenty of unused names still on the table. Joseph, Luke, Augustine, Basil, Athanasius all remain options.