Pope Leo XIV, the first ever pontiff from the US, has given his first major address during his inauguration ceremony attended by world leaders and thousands of faithful.
Leo marked the start of his papacy by calling for unity within the church and for it to act as a “leaven of harmony for humanity”.
UK Foreign Secretary David Lammy, Deputy Prime Minister Angela Rayner and the Duke of Edinburgh, who was representing the King, were among attendees at the outdoor Mass in the Vatican on Sunday morning.
They joined politicians from across the world including Ukrainian President Volodymyr Zelensky; US Vice President JD Vance, who converted to Catholicism as an adult; Peruvian President Dina Boluarte and Canadian Prime Minister Mark Carney.
Ahead of the ceremony, Leo took his first popemobile ride through St Peter’s Square, waving from the back of the open-back vehicle to the jubilant crowd who carried flags and cheered “Viva il Papa”.
Leo appeared to choke up when the two symbols of the papacy were placed on him during the Mass: the pallium, a woollen stole, over his shoulders and the fisherman’s ring on his finger.
The pontiff appeared thoughtful as he held a hand over his chest as a part of the Gospel was chanted in Greek during the Mass, later smiling and nodding as he was applauded by the crowds.
The inauguration of the pope is a hugely important moment for Catholics around the world.
— Keir Starmer (@Keir_Starmer) May 18, 2025
I warmly welcome Pope Leo XIV to the role and wish him the very best as he leads the Catholic Church into this new chapter.
During his homily, the Pope paid tribute to his predecessors Pope Francis and Pope Leo XIII, and called for unity within the church.
He said: “I would like that our first great desire be for a united church, a sign of unity and communion, which becomes a leaven for a reconciled world.
“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 marginalises the poorest.”
Congratulations His Holiness Pope Leo XIV on your inauguration today.
— Angela Rayner (@AngelaRayner) May 18, 2025
This historic moment marks the next chapter in the Catholic Church’s journey. It was a privilege to represent the UK and its Catholic community at Mass.
He added: “The heart of the gospel is the love of God that makes us brothers and sisters.
“With my predecessor, Leo XIII, we can ask ourselves today, if this criterion were to prevail in the world, would not every conflict cease and peace return?
“With the light and the strength of the Holy Spirit that is still the church founded on God’s love, a sign of humanity, 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.”
Prime Minister Sir Keir Starmer wished Leo the “very best” in a post on X on Sunday evening.
Sir Keir wrote: “The inauguration of the pope is a hugely important moment for Catholics around the world.
“I warmly welcome Pope Leo XIV to the role and wish him the very best as he leads the Catholic Church into this new chapter.”
After the ceremony, Ms Rayner sent the Pope her “congratulations”, saying it was a “privilege” to attend the ceremony in a message posted on social media.
On X, the deputy prime minister wrote: “Congratulations His Holiness Pope Leo XIV on your inauguration today.
“This historic moment marks the next chapter in the Catholic Church’s journey.
“It was a privilege to represent the UK and its Catholic community at Mass.”
Following the ceremony, Leo met Irish President Michael D Higgins with the pair smiling as they shook hands.
The new Pope, formerly Cardinal Robert Prevost from Chicago, was elected on May 8 after a conclave meeting of 133 cardinals from 70 countries in just over 24 hours.
Three UK cardinals took part in conclave, Cardinal Vincent Nichols, Cardinal Timothy Radcliffe and Rome-based Cardinal Arthur Roche, as did Irish-born Cardinal Kevin Farrell who has mainly ministered in the US and been based in Rome for some years.
In the days since his election, the 69-year-old has outlined some of his key priorities as Pope, saying the Holy See’s three pillars of diplomacy are peace, justice and truth during his first foreign policy address.
During his first Sunday blessing earlier this month, Leo called for a just and lasting peace in Ukraine and an immediate ceasefire in Gaza.
Leo has also identified artificial intelligence as one of the most critical issues facing humanity, saying it poses challenges to defending human dignity, justice and labour.
He is a dual citizen of the United States and Peru, where he first served as a missionary and then as archbishop, meaning he is the first Pope from each country.
The new pontiff is the 267th Pope, becoming the religious leader of some 1.4 billion Catholics across the globe.
He follows in the footsteps of the late Pope Francis, whose popularity saw him dubbed “the people’s Pope”.
