Pope Leo XIV marked a high point of his first foreign trip to Turkey with a pilgrimage to the site where early Christian church leaders met 1,700 years ago under the auspices of the Roman Emperor Constantine to host the Council of Nicaea.

Leo on Friday prayed for Christian unity with Ecumenical Patriarch Bartholomew, spiritual leader of the world’s Orthodox Christians, at the site of the A.D. 325 gathering, now the town of Iznik.

The unprecedented gathering of at least 250 bishops from around the Roman Empire during the first council established the first version of the Nicene Creed, a statement of faith that millions of Christians still recite each Sunday.

Eastern and Western churches were united until the Great Schism of 1054, a divide precipitated largely by disagreements over the primacy of the pope.

The American pope has emphasized a message of peace and a plea to help end wars in Ukraine and Gaza during his trip to Turkey and Lebanon, which lasts through Tuesday.

On Thursday, he met in the capital Ankara with President Recep Tayyip Erdogan and encouraged Turkey to be a source of stability and dialogue in a world riven by conflict.

Leo then traveled to Istanbul to carry not only his message of unity among Christians at Iznik, located southeast of the city, but also to reinforce the church’s relations with Muslims.

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

AP video shot by: Paolo Santalucia

Production: Trisha Thomas