This Pope Reigned Longer Than Any Other, and It’s Not Even Close

With Pope Francis's death on Monday, April 21, 2025, the Roman Catholic Church around the world is entering a period of mourning. That mourning period that will culminate in the election of a new pontiff. As we remember Pope Francis and the 12 years and 42 days he held his position, it begs the question: which Pope held the title the longest? Follow along as we share the answer, along with a number of other interesting Papal facts.

In the next 20 days, the Roman Catholic Church will begin its process to elect a new head of state for the Vatican, the bishop of Rome, and the leader and highest diplomat of the global Catholic Church. The papal conclave begins soon, with the most senior figures in the College of Cardinals going behind closed doors and holding a highly secretive ballot process until one candidate receives a two-thirds majority. Any Cardinal younger than 80 years old is eligible to vote.

To say that the vote for the new Pope is highly secretive is an understatement, as this is arguably one of the most secretive votes in the world's history. While outdated in a digital world, the process upholds hundreds of years of tradition. It occurs in the Sistine Chapel, one of the most revered places in the Catholic Church, where no outside communication occurs until the vote ends.

Once a new Pope is elected, the public outside Vatican walls will know the election has ended once white smoke is released above the chapel. If the smoke is black, voting will continue, but once a candidate is elected, they will be dressed in papal robes, pick their papal name, and appear on St. Peter’s Basilica balcony to announce their election to the world.

With just a 13-day reign, Pope Urban VII had the shortest serving time in office before passing away on September 27, 1590. In 1896, Pope Boniface VI reigned for 16 days, while Pope Celestine IV held office for 17 days. Ultimately, the lesson is that some Popes can hold office for decades, while others barely get used to their papal robes before their health fails them.

Pope Urban VIII served 20 years, 11 months, and 24 days, making him the 11th-longest-serving Pope in history. The 236th Pope, born Maffeo Barberini, was an Italian cleric before serving from 1623 to 1644. Heavily involved in Italian and European political disputes, his papacy spanned much of the Thirty Years’ War between 1618 and 1648, which helped reshape Europe.

Holding office between 400 and 461, Pope Leo I served for 7,713 days or a total of 21 years, 1 month, and 13 days. Little is known about his early life, but he was known as Leo the Great for convincing Attila the Hun not to destroy and plunder Rome of its riches and treasures.

Pope Sylvester I was the ninth-longest-serving Pontiff, holding office for 21 years, 11 months, and 1 day (8,005 days). Born in 285, Pope Sylvester held his office between 314 and 335. When he took office, the Edict of Milan in 313 had just granted religious freedom to Christians, which ended centuries of persecution.

The 171st Pope, Pope Alexander III, served between 1159 and 1181, holding his office for 21 years, 11 months, and 42 days, or 8,029 days. His reign was marked by major church reforms, including rescinding papal independence from the Holy Roman Emperor and the King of England, while addressing church abuse and heresy. He also instituted the two-thirds rule to elect a new pope, which still exists today.

As the seventh-longest-serving pope, Pope Pius VII held office for 23 years, 5 months, 7 days, or 8,560 days. Among his accomplishments, Pope Pius VII reestablished the Catholic Church in France, secured freedom for French Catholics, and attended Napoleon’s coronation in 1804. While he opposed slavery, he stripped away Jewish freedom by reversing Napoleon’s reforms for persecuted groups.

Holding office from 772 until he died in 795, Pope Adrian I held office for 8,729 days or 23 years, 10 months, and 25 days in total. Adrian was well-known for strengthening the papal power of the day, including restoring much of Rome’s city walls, building new churches, and expanding charitable giving and activity, leaving him well remembered for statesmanship and administrative abilities.

With 8,962 days in office, Pope Pius VI held his position for 24 years, 6 months, and 15 days. Serving as the head of the church between 1775 and 1799, his reign was the longest of the 18th century and included the Enlightenment, the French Revolution, and Napoleon's rise to power. Pope Pius VI was strongly against the French Revolution, leading Rome to be occupied by French forces, and he was exiled after refusing to renounce his power.

The fourth-longest-serving Pope, Pope Leo XIII, was in office for 9,281 days, 25 years, 5 months, and 1 day. The 257th Pope served from 1878 until he died in 1903. Born into Italian nobility, Pope Leo XIII became a Cardinal in 1853 and, upon becoming Pope, famously laid the foundation for Catholic social teaching, earning the title of the “Pope of the Workers.”

Pope Francis’ predecessor, Pope John Paul II, was the first non-Italian pope in 455 years, and the first pope to visit the White House and a mosque. Traveling more than any other Pope in history, Pope John Paul II held his office for 26 years, 5 months, and 17 days, or a total of 9,665 days. The Pope played a major role in ending communism in Eastern Europe, including Poland, his home country.

Serving 31 years, 7 months, and 23 days, or a total of 11,560 days, Pope Pius IX was the second longest serving Pope in history. The caveat is that Pope Pius IX’s reign is the longest verified in papal history, and marks the pope’s turn from a temporal ruler to that of a spiritual leader. His work included granting amnesty to political prisoners and introducing limited reforms inside the Papal state as the first of the modern papacy.

Believed to be the longest-serving Pope in history, Saint Peter was thought to have reigned for 34 years. Saint Peter is said to be one of the 12 Apostles of Jesus and is regarded as one of the foundational leaders of the early Church. According to biblical accounts, Peter was part of Jesus’ inner circle and was present at major historical events.