The Catholic faithful came by the tens of thousands to see the formal inauguration of Pope Leo XIV, the first American pontiff, in an event marked by ancient tradition and pleas for church openness and peace around the world.
The pilgrims were joined by more than 150 dignitaries, including Prime Minister Mark Carney, Ukrainian President Volodymyr Zelensky and Israeli President Isaac Herzog. Notably absent was U.S. President Donald Trump, who had come to Rome earlier this month to attend the funeral of Pope Francis, who died at the age of 88 on April 21.
Pope Leo XIV, history’s first American pope, vowed Sunday to work for unity so that the Catholic Church becomes a sign of peace in the world, offering a message of communion during an inaugural Mass in St. Peter’s Square before an estimated 200,000 pilgrims, presidents, patriarchs and princes.
The Associated Press
The official Vatican News site said 200,000 pilgrims attended the mass. They packed St. Peter’s Square and the long, wide boulevard leading from St. Peter’s Basilica all the way to the Tiber River. Many were waving flags from their home countries, or flags with “Peace” emblazoned on them. Jews, Muslims, Hindus, Buddhists, Sikhs, Zoroastrians and Jains were among the religious delegations who attended the celebration.
Mr. Carney, who had missed Francis’s funeral because of the federal election, arrived in Rome on Saturday. The Prime Minister, who is a devout Catholic, his wife, Diana, and their daughter Cleo briefly met Leo in St. Peter’s Basilica shortly after the mass ended at noon Rome time. On X, Mr. Carney said: “His message of unity and compassion inspires the best in us all.”
The photo showed him and the Pope shaking hands. Mr. Carney was one of the few world leaders to kneel during the blessing of the Eucharist, and was seen using his phone to take pictures of the Pope before the mass started and after it had concluded.

Canadian Prime Minister Mark Carney and Ukrainian President Volodymyr Zelensky met at Pope Leo's inaugural mass.ISABELLA BONOTTO/AFP/Getty Images
The 267th Pope’s arrival mixed modern statecraft with ritual that has barely changed in centuries.
Leo, 69, the former Cardinal Robert Francis Prevost, arrived in an electric, open-back Mercedes. At one point, the “popemobile” stopped briefly so he could kiss a child. During his tour of the square, there were chants of “Viva il Papa” and loud applause.
The mass was delivered mostly in Italian and Latin, but there were readings in other languages, including English, as the pilgrims who could not clearly see the altar watched the event on massive video screens.
The mass started when Leo entered St. Peter’s Basilica alongside a procession of cardinals. Inside, he received two gifts that symbolize the papacy.
Pope Leo XIV waves to Catholic faithful at his inaugural mass at the Vatican on May 18.Yara Nardi/Reuters
The first was a gold signet fisherman’s ring, which is named in honour of St. Peter, a fisherman who became the first pope 2,000 years ago. The ring represents the beginning and end of a papacy, and when a pontiff dies, it is destroyed.
The second gift was a lamb’s wool pallium, which symbolizes the pope’s role as a shepherd. It was placed over his shoulders and worn during the mass.
When he was elected Pope after a remarkably fast, 25-hour conclave that finished on May 8, his first words from the loggia of St. Peter’s Basilica were, “Peace be with you all.”
On Sunday morning, his homily picked up on the theme as wars continue to lay waste to Ukraine and Gaza.
“In this our time, we still see too much discord, too many wounds caused by hatred, violence, prejudice, the fear of difference, and an economic paradigm that exploits the Earth’s resources and marginalizes the poorest,” he said.
“Listen to his offer of love and become his one family: In the one Christ, we are one. This is the path to follow together, among ourselves but also with our sister Christian churches, with those who follow other religious paths, with those who are searching for God, with all women and men of goodwill, in order to build a new world where peace reigns!”
The pilgrims and tourists had flooded into St. Peter’s Square well before dawn to ensure they could see Leo mark his official debut as the leader of 1.4 billion Catholics. By 7 a.m., three hours before the start of his inaugural mass, some had fallen asleep on their chairs in the warm morning Roman sun as visitors from all over the world held their positions for fear of losing their chairs.
Some came from Peru, where Leo worked as an Augustine Order missionary priest for 20 years; others from the United States to celebrate the debut of the first American pontiff, who is from south Chicago.
Some faithful came from the United States to celebrate the debut of the first American pontiff.Alessandro Garofalo/Reuters
Molly Milroy, 47, a freelance writer who lives in Minnesota but lived in Chicago early in her career, travelled to Rome out of a sense of patriotism and Catholic calling. She wore a cap with the City of Chicago flag on it.
“Having an American pope is incredible,” she said. “I felt the call to come here in my heart, maybe the Holy Spirit. I feel more American. And he is someone who roots for the White Sox!”
Mr. Trump’s absence from the mass pleased some visitors.
“Why did Trump not come?” asked Pino Cavuoti, 64, a radio journalist who is a member of a Catholic charity fraternity in the region of Abruzzo, in central Italy. “He probably wanted to make more money during his tour of Gulf states. But from what I have read, he and Leo would not get along anyway.”
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The White House was represented at Leo’s mass by Vice-President JD Vance, Secretary of State Marco Rubio and their entourages.
Among the heads of state or government who attended the mass were Britain’s Prince Edward; Argentine President Javier Milei; Anthony Albanese, the newly re-elected Prime Minister of Australia; and Germany’s new Chancellor, Friedrich Merz.
World dignitaries including Italian Prime Minister Giorgia Meloni and U.S. Vice-President JD Vance sat with dignitaries at Saint Peter’s Square for the mass.VINCENZO LIVIERI/Reuters
Two sisters from Bergamo, in northern Italy – Domenica and Marina Bianchi, both business administrators – arrived in St. Peter’s Square at 4 a.m. They said they approved of Pope Leo because of his messages of peace and because they thought that he could lure back some of the faithful who had abandoned the church in recent decades.
Pope Leo XIV has taken his first popemobile ride through St. Peter’s Square ahead of installation, waving from the back of the open-back truck to the crowd waving flags and cheering “Viva il Papa!”
The Associated Press
“The church in general lost the faithful,” Domenica said. “Pope Leo might be able to change this. Francis was a bit too liberal.”
Leo’s peace message on Sunday resonated with many of the pilgrims.
At the end of the mass, Leo invited all Christians to be enlightened by the Holy Spirit so they can build a church “founded on God’s love, a sign of unity, a missionary church that opens its arms to the world, proclaims the word, allows itself to be made restless by history, and becomes a leaven of harmony for humanity.”