The solemn inauguration of Pope Leo XIV’s papacy will unfold at 10 a.m. (Rome time) on Sunday, May 18, in the heart of St. Peter’s Square. This sacred liturgy heralds the formal commencement of his role as Bishop of Rome and successor to the Apostle Peter. The ceremony is steeped in symbolism and features key adjustments from Pope Francis' 2013 inauguration.

The Mass begins at the Altar of the Confession beneath Bernini’s grand baldachin. Pope Leo XIV, flanked by patriarchs from the Eastern Churches, will descend into the crypt to offer prayers at the tomb of St. Peter. There, amid flickers of incense rising from the thurible, he will pay reverent homage to the first pope—an act affirming apostolic continuity.

In a ceremonial procession that bridges past and present, deacons will bear the pallium, the Fisherman’s Ring, and the Book of the Gospels out from the basilica into the square. The air will echo with the ancient “Laudes Regiae” hymn, invoking the saints’ intercession as the pontiff steps into his global spiritual mission.

Upon reaching the altar, Pope Leo XIV will invoke the Trinity with the Latin sign of the cross: “In nomine Patris, et Filii, et Spiritus Sancti. Amen.” He will then bless the gathered faithful with holy water—a gesture of spiritual renewal and protection.

In a powerful gesture of ecclesial unity, the Gospel will be proclaimed in both Greek and Latin—representing the twin lungs of the Church. Greek, the tongue of the Eastern Church and early Christians; Latin, the language of the Western tradition. This dual proclamation underscores the pope’s embrace of both liturgical heritages within the universal Church.

Abandoning the cardinal’s ring he previously wore, Pope Leo XIV will receive the Fisherman’s Ring—a gold symbol of his role as Peter’s successor, historically used to seal papal documents. He will also be vested with the pallium, a white woolen band adorned with black crosses, symbolizing his pastoral responsibility over the global flock. Its form—a stylized Y—echoes the yoke of Christ and the burden of service.

One of the most notable departures from past protocol is who will pledge fidelity. Unlike the 2013 Mass, where cardinals alone affirmed obedience, Pope Leo XIV will receive this pledge from a diverse group of faithful laity—representatives of the People of God. This reflects an expanded vision of ecclesial communion.

The celebration culminates with Pope Leo XIV’s inaugural homily—his first formal address as pontiff. This message will offer insight into the spiritual tone and pastoral vision he intends to set as he begins his Petrine ministry.