Where is Nicaea, birthplace of the Nicene Creed?

In 2025, the Jubilee of the Incarnation is being accompanied by another celebration: the 1,700th anniversary of the Council of Nicaea (pronounced “niCEEya”). The council reaffirmed the divinity of the Son of God against the Arian heresy, and drew up the creed that is still recited at Sunday Mass.

But where is Nicaea? And what does the name mean? The city was originally Greek; its name comes from “victory” in the Hellenic language. Today, it’s in Turkey, and is called İznik. The city is built on the eastern shore of a lake that bears its name, about a hundred kilometers (62 miles) southeast of Istanbul, on the other side of the Sea of Marmara.

It’s a modern city now, but there are still many archaeological remains from antiquity, testifying to the city's glorious and tumultuous past. Its founding remains mysterious, but it seems that the first clear knowledge of its existence comes from the 4th century BC. Lysimachus, one of Alexander the Great's diadochi, took the city from one of his adversaries and renamed it Nicaea. 

Under the Roman Empire, starting in 72 BC the city was part of Bithynia. It was certainly visited by Pliny the Younger, Trajan's legate in this province between 111 and 113. In fact, he mentioned in a letter to the emperor the presence of Christians in Nicaea, a sign of a region that knew Christ early on.

Nicaea was close to Constantinople and was a prosperous administrative center. For this reason, Constantine chose it to host the council fathers in 325 in order to rule on the question of the Arian heresy. Four hundred years later, in 787, Empress Irene convened another council, “Nicaea II,” on the shores of the lake to resolve the iconoclastic crisis.

However, this city of the Byzantine empire quickly experienced a complicated history, made up of rebellions and then attacks by the Seljuk Turks, into whose hands it fell in 1081. Recaptured, it would experience one last period of Greek glory after the siege of Constantinople in 1204.

While the Latins diverted the Fourth Crusade to seize the imperial capital, a Greek state came into being. Known as the Empire of Nicaea — since that was where the capital was established — it covered a broad swath of land from the Black Sea to the Ionian Sea. But as soon as Constantinople was recaptured in 1261, Nicaea declined until it was besieged for three years and fell to the Ottomans in 1331.

Walls over three kilometers long, five meters thick, and ten meters high, monumental gates, remains of ancient columns and ruins of 4th-century buildings, temples, churches, synagogues, thermal baths ... Archaeology is finding an abundance of material in Iznik today. Until the war between the Turks and Greeks in 1922, you could even admire a beautiful Church of the Dormition. As for the Hagia Sophia, which hosted the debates of Nicaea II, it became a mosque again in 2011, like its big sister in Istanbul a few years later.

The most impressive of the heritage discoveries dates from 2014. Flying over Lake Iznik, the passengers of a helicopter spotted the remains of a building in the water. It’s a Byzantine basilica, St. Neophytos, which was presumably built in the 4th century. It’s located under 2 meters (almost 7 feet) of water, 66 feet from the shore!