Pope Leo XIV’s inaugural journey abroad takes a significant turn as he embarks on a pilgrimage to Turkey, visiting the historic site where early Christian leaders gathered 1,700 years ago under Emperor Constantine’s rule for the Council of Nicaea.

At this iconic location, now known as the town of Iznik, Pope Leo is set to join Ecumenical Patriarch Bartholomew, the global head of Orthodox Christians, in prayer. Together, they will sign a joint declaration symbolizing Christian unity, harking back to the historic meeting of 325 AD.

During the first council, an unprecedented assembly of over 250 bishops from across the Roman Empire laid the foundation for the Nicene Creed—a declaration of faith that remains integral to Christian worship today. The Eastern and Western branches of Christianity remained unified until the Great Schism in 1054, primarily caused by disputes regarding papal authority.

In his visit spanning from November 27 to December 2, which includes stops in Turkey and Lebanon, the American pope has been advocating for peace, urging an end to conflicts in Ukraine and Gaza. During his Thursday meeting in Ankara with President Recep Tayyip Erdogan, he encouraged Turkey to act as a beacon of dialogue and stability amid global turmoil.

Following his visit to Ankara, Pope Leo traveled to Istanbul, where he continues to champion Christian unity at Iznik, located southeast of the city, while also aiming to strengthen ties with the Muslim community.

Leo also is due to visit the Blue Mosque and preside over an interfaith meeting in Istanbul.

Here’s the latest:

Pope will open day at cathedral and nursing home

Pope Leo XIV is to start the second day of his tour of Turkey and Lebanon meeting bishops and other church officials at the Cathedral of the Holy Spirit, a 19th-century Baroque church in Istanbul’s Sisli district.

He then is scheduled to visit a nearby nursing home run by the Little Sisters of the Poor, an order founded in France in the 1840s to care for poverty-stricken older people.

Leo to visit Council of Nicaea site

After his stops at the cathedral and nursing home, the pope is set to take a short helicopter ride to Iznik, a town south of Istanbul known in Roman times as Nicaea. It was here that the Council of Nicaea was held in 325 AD to produce the Nicene Creed, a statement of faith that millions of Christians still recite each Sunday.

Leo will pray with Ecumenical Patriarch Bartholomew, spiritual leader of the world’s Orthodox Christians, at the site of the gathering, which is today marked by the ruins of the Basilica of Saint Neophytos, built some 50 years after the council.

After returning to Istanbul, he will hold a private meeting with bishops at the Apostolic Delegation, which serves as the Vatican’s consulate in the city.