From AP:
Pope Leo XIV traveled to join Orthodox patriarchs in commemorating an important moment in Christian history, gathering at the site in Turkey of an unprecedented A.D. 325 meeting of bishops to pray that Christians might once again be reunited.
Leo, Ecumenical Patriarch Bartholomew I and other Christian leaders were meeting on the shores of Lake Iznik, the site of the Council of Nicaea that produced a creed, or statement of faith, that is still recited by millions of Christians today. Leo flew by helicopter to Iznik from Istanbul to take part in an ecumenical prayer to commemorate the 1,700th anniversary of the Nicaea meeting, the highlight of his visit to Turkey. He arrived just after the Muslim call to prayer rang out from a nearby mosque.