By Christoph Sator, Christoph Driessen, Manuel Schwarz

Vatican City/Rome (Italy) - Pope Leo XIV (69) was officially inaugurated on Sunday with a solemn mass in front of around 100,000 people in St. Peter's Square. In his first sermon , the new leader of 1.4 billion Catholics worldwide urged his church to remain united.

At the same time, he criticized an economic model that exploits the world's resources and pushes the poorest to the margins.

With the mass, the US-American Robert Francis Prevost also received all the insignia of his office. After a prayer at the tomb of St. Peter the Apostle in St. Peter's Basilica, he received the traditional fisherman's ring and the pallium, a kind of scarf. The ring is a reminder of Peter, who was a fisherman. According to Catholic doctrine, Leo, as the representative of Christ on earth, is also supposed to act as a "fisher of men".

As the successor to Pope Francis (†88), the 69-year-old former cardinal is the first American to head the Catholic Church. He also has citizenship of the South American country from his time as a missionary and bishop in Peru.

The Peruvian head of state Dina Boluarte (62) was among the guests of honor at the inauguration, as was US Vice President JD Vance (40).

Dozens of presidents, heads of government and high-ranking representatives of royal houses and other churches took part in the fair. There was talk of more than 150 delegations in total. Federal Chancellor Friedrich Merz (69, CDU) attended on behalf of Germany.

In his sermon, delivered in Italian, Leo expressed his humility. "I was chosen without any merit and come to you with fear and trembling," he confessed. He then emphasized the unity of the Church as his greatest wish: "Dear brothers and sisters, I would like this to be our first great desire: a united Church."

He was alluding to the struggles for direction within the universal Catholic Church. The reformers - which include the majority of German bishops - are pushing for a more liberal sexual morality and the opening of church ministries to women.

The conservatives, on the other hand, want to keep traditional doctrine unchanged and reject blessings for homosexual couples, for example. In Germany, the church has been losing members for many years.

Leo himself is regarded as a moderate bridge-builder (literally: pontiff) who can mediate between the different camps. It is widely assumed that this is one of the reasons why he was elected so surprisingly quickly by the conclave. The election took less than 24 hours.

In his sermon, the first pope from the USA made it clear that he sees himself in the line of his Argentinian predecessor Francis, who was particularly committed to helping people on the margins of society. "In our time, we are still experiencing too much discord, too many wounds caused by hatred, violence, prejudice, fear of the other and an economic model that exploits the earth's resources and marginalizes the poorest," said Leo.

In doing so, he explicitly took a different stance to his compatriot, US President Donald Trump (78).

Francis had also emphasized in the sermon at his inauguration in 2013 that the Church must take care of the "poorest, weakest, least" and appealed to preserve creation.