A teenager who died of leukaemia in 2006 became the first Catholic saint of the millennial generation on Sunday (September 7), in a Vatican ceremony led by Pope Leo and attended by an estimated 70,000 young worshippers from dozens of countries.

Carlo Acutis, a British-born Italian boy who died aged 15, learned computer code to build websites to spread his faith. His story has drawn wide attention from Catholic youth, and he is now at the same level as Mother Teresa and Francis of Assisi.

Leo, the first U.S. pontiff, canonised Acutis on Sunday along with Pier Giorgio Frassati, a young Italian man who was known for helping those in need and died of polio in the 1920s.

Acutis' canonisation had been hotly anticipated by many Catholic youths for months. It was originally set for April but was postponed after the death of Pope Francis.

Sunday's event is the first time that Leo, elected pope by the world's cardinals in May, has presided over such a ceremony.

DESCRIPCIÓN DE IMÁGENES

VATICAN CITY (SEPTEMBER 7, 2025) (VATICAN MEDIA - Access all)

1. CROWDS IN ST PETER'S SQUARE AT CEREMONY TO CANONISE NEW SAINTS

2. (SOUNDBITE) (Italian) POPE LEO, SAYING: (SOUNDBITE CONTINUES OVER SHOT OF POPE SPEAKING)

"Today, this is a wonderful celebration for all of Italy, for all of the Church, for all of the world."

3. CROWDS CHEERING IN SQUARE

4. PICTURE OF PIER GIORGIO FRASSATI, A YOUNG ITALIAN MAN WHO DIED OF POLIO IN THE 1920S

5. PICTURE OF CARLO ACUTIS, A BRITISH-BORN ITALIAN BOY WHO DIED OF LEUKAEMIA IN 2006

6. (SOUNDBITE) (Italian) POPE LEO, SAYING: (SOUNDBITE CONTINUES OVER SHOT OF POPE SPEAKING)

"In this setting, today we look to Saint Pier Giorgio Frassati and Saint Carlo Acutis: a young man from the early 20th century and a teenager from our own day, both in love with Jesus and ready to give everything for him."

7. PRESIDENT OF ITALY, SERGIO MATTARELLA, AT CEREMONY

8. MAN HOLDING PICTURE OF ACUTIS

9. (SOUNDBITE) (Italian) POPE LEO, SAYING: (SOUNDBITE CONTINUES OVER SHOTS OF PICTURE OF ACUTIS AND ACUTIS' MOTHER, ANTONIA SALZANO SEATED)

"Carlo, for his part, encountered Jesus in his family, thanks to his parents, Andrea and Antonia — who are here today with his two siblings, Francesca and Michele."

10. ST PETER'S SQUARE

11. (SOUNDBITE) (Italian) POPE LEO, SAYING:

"Both Pier Giorgio and Carlo cultivated their love for God and for their brothers and sisters through simple acts, available to everyone: daily Mass, prayer, and especially Eucharistic Adoration. Carlo used to say: 'In front of the sun, you get a tan. In front of the Eucharist, you become a saint!'"

12. CROWD IN ST PETER'S SQUARE

13. (SOUNDBITE) (Italian) POPE LEO, SAYING: (SOUNDBITE CONTINUES OVER SHOT OF POPE SPEAKING)

14. DRONE SHOT OF ST PETER'S SQUARE

15. CEREMONY IN PROGRESS

16. (SOUNDBITE) (Italian) POPE LEO, SAYING:

"Another essential practice for them was frequent confession. Carlo wrote: 'The only thing we really have to fear is sin;' and he marvelled because — in his own words — 'people are so concerned with the beauty of their bodies and do not care about the beauty of their souls.'"

17. VARIOUS OF PEOPLE CLAPPING

18. (SOUNDBITE) (Italian) POPE LEO, SAYING: (SOUNDBITE CONTINUES OVER SHOTS OF MATTARELLA SEATED AND POPE SPEAKING)

"Dear brothers and sisters, before concluding this long-awaited celebration, I wish to greet and thank all of you who have come in such great numbers to celebrate two new saints. To the intercession of the saints and the Virgin Mary, we entrust our constant prayer for peace, especially in the Holy Land, in Ukraine, and in every other country bloody from war. To government leaders, I repeat: Listen to the voice of conscience. The apparent victories achieved with weapons, sowing death and destruction, are in fact defeats and never bring peace or security. God does not want war. God wants peace."

19. PRIESTS CLAPPING

20. DRONE SHOT OF ST PETER'S SQUARE