Pope Leo's upcoming visit to Iznik puts small Turkish town on map

Archaeologist Mustafa Sahin has spent nearly a decade working at Lake Iznik, tucked between rolling hills in western Turkey.

The excavations he is leading at the relatively unknown site point to one of the most important events in Christian history. Its fame will rise after Pope Leo visits on Friday, as part of his first overseas visit since his election in May.

“Of course, the fact that it is recognised worldwide and that Pope Leo XIV, one of the most prominent religious leaders in Christianity, will visit this place makes me very proud and very happy,” Mr Sahin, of Bursa Uludag University, told The National.

It is 1,700 years since hundreds of bishops from across the Roman Empire convened in Iznik, also known as Nicaea, for a meeting to settle a major dispute in Christian belief.

Pope Leo will lead prayers at the archaeological site of St Neophytos Church in Iznik. Robert Badendieck for The National

The most significant outcome was the Nicene Creed – a proclamation that Jesus is equal to God the Father. In a slightly modified form, it is still recited in church services around the world, across most denominations.

It is a profession of faith that “unites all Christians”, Pope Leo XIV wrote in a papal letter published on Sunday. “In these difficult times we are living, amid so many concerns and fears, threats of war and violence, natural disasters, grave injustices and imbalances, and the hunger and misery suffered by millions of our brothers and sisters, this creed gives us hope.”

Prof Sahin believes that the council meeting in AD325 took place at the archaeological site, now on the shores of Lake Iznik.

Originally spotted in aerial photography in 2014, the site was underwater for years until Lake Iznik's levels receded, revealing the ruins of the Basilica of Saint