In a rare event, Pope Tawadros II, head of the Coptic Orthodox Church, joined Pope Francis during the Catholic pope’s General Audience last week.

“It is with great joy that I welcomed today His Holiness Tawadros II, Pope of Alexandria and Patriarch of the See of St. Mark, beloved brother and dear friend, with whom I celebrated the 50th anniversary of the historic meeting between Pope St. Paul VI and Pope Shenouda III,” the pope said in a tweet after Wednesday’s meeting.

It was the first time another pope had spoken during the General Audience, an event held to mark the 50th anniversary of the historic Joint Christological Declaration signed by St. Paul VI and Pope Shenouda III of Alexandria, according to a Vatican News report.

Ten years had passed since Pope Tawadros II had set foot in St. Peter's Square. During his 2013 visit, Tawadros proposed that May 10 should be designated as the "Day of Coptic-Catholic Friendship.” That was a suggestion that struck a chord with Pope Francis. The two have since made it a tradition to connect via phone every year to further solidify the bond between their two Churches, Vatican News said.

"Dear friend and brother Tawadros, thank you for accepting my invitation on this dual anniversary, and I pray that the light of the Holy Spirit may illuminate your visit to Rome, the important meetings you will have here, and in particular our personal conversations,” Pope Francis said during the ceremony. "I thank you from my heart for your commitment to the growing friendship between the Coptic Orthodox Church and the Catholic Church."

May 1973 was when Pope Paul VI and Pope Shenouda III, leader of the Coptic Orthodox Church at that time, came together for a momentous meeting. It was the first time the two Church leaders had met for serious conversation in more than a millennium. During that historic encounter, the two agreed to put an end to a long-standing Christological disagreement and forged an agreement between the Catholic and Coptic Orthodox Churches, the report said.

“Despite the differences in our roots and affiliations,” said Pope Tawadros, “we are united by the love of Christ who dwells within us, and the host of our Apostolic Fathers and saints which surrounds and guides us,” Vatican News said.