Turkey: The 1,700th anniversary of one of the most pivotal events in Christian history the First Council of Nicaea has officially commenced in the ancient city of Iznik, formerly known as Nicaea. This historic gathering, originally convened in 325 AD by Roman Emperor Constantine I, marked the first ecumenical council in the life of the Christian Church and laid the theological groundwork still recognized today.

The celebrations began on Tuesday, May 20, honoring a council that brought together approximately 318 bishops from across the Roman Empire. Convened in response to the growing influence of Arianism—a doctrine that denied the full divinity of Jesus Christ—the Council of Nicaea sought to preserve doctrinal unity and reaffirm the core truths of the Christian faith.

The central outcome of the council was the formulation of the Nicene Creed, a powerful declaration of belief that rejected the teachings of Arius, who asserted that Christ was created by God and therefore not co-eternal or equal in essence. The Creed firmly established the doctrine of the Holy Trinity—affirming the equality of the Father, Son, and Holy Spirit—as well as the salvific mission of Jesus Christ.

This theological milestone became the cornerstone for Catholic, Eastern Orthodox, Anglican, and most Protestant traditions. It has since stood as a testament to Christian unity and identity, shaping liturgy and belief for nearly two millennia.

Though convened in the 4th century, the impact of the Council of Nicaea reverberates through history. The Nicene Creed was revisited and reaffirmed at the Council of Constantinople in 381 AD, ensuring its permanence in Christian doctrine. Of the 21 ecumenical councils recognized throughout Church history, Nicaea remains the foundational one. The most recent, the Second Vatican Council (1962–1965), continued the Church’s tradition of collective discernment and doctrinal clarification.

In honor of this historic anniversary, Pope Leo XIV has expressed his desire to make a pilgrimage to Nicaea, symbolizing the continued relevance of the council and its message of unity in faith. His gesture underscores the enduring importance of dialogue, reflection, and shared belief in a world where divisions often challenge spiritual cohesion.

As the global Christian community reflects on this milestone, the 1,700th anniversary of the Council of Nicaea serves as a powerful reminder of the Church’s ongoing journey to preserve the truth, foster unity, and pass down the faith from generation to generation.