Pope Francis has proposed celebrating the 1,700th anniversary of the First Council of Nicaea together with Orthodox leaders in a personal letter to Ecumenical Patriarch Bartholomew of Constantinople.

The letter, published by the Vatican on Saturday, was delivered by Cardinal Kurt Koch — who heads the Dicastery for Promoting Christian Unity — during a visit to Istanbul for the patronal feast of the Orthodox Church.

“The now imminent 1,700th anniversary of the First Ecumenical Council of Nicaea will be another opportunity to bear witness to the growing communion that already exists among all who are baptized in the name of the Father and of the Son and of the Holy Spirit,” Francis wrote in his message dated Nov. 30.

Reflecting on six decades of Catholic-Orthodox dialogue while looking ahead to future possibilities for unity, the Pope acknowledged the progress made since Vatican II’s Unitatis Redintegratio decree marked the Catholic Church’s official entry into the Ecumenical Movement 60 years ago.

Speaking to EWTN News about this anniversary on Nov. 21, Koch emphasized that unity efforts must focus on “the innermost center of self-revelation in Jesus Christ.”

The Swiss Cardinal also highlighted what he called an “ecumenism of blood,” noting that “Christians are not persecuted because they are Catholic, Lutheran, or Anglican but because they are Christians.”

Building peace in a time of war

While celebrating the “renewed fraternity” achieved since Vatican II, Pope Francis noted in his message that full communion, particularly sharing “the one Eucharistic chalice,” remains an unfulfilled goal.

In a pointed observation about contemporary global tensions, the Pontiff connected ecumenical efforts to peace-building.

“The fraternity lived and the witness given by Christians will also be a message for our world plagued by war and violence,” he wrote, specifically mentioning Ukraine, Palestine, Israel, and Lebanon.

The Pope also highlighted the recent participation of Orthodox representatives in October’s Synod on Synodality.

The traditional exchange of delegations between Rome and Constantinople occurs twice yearly, with Catholic representatives traveling to Istanbul for St. Andrew’s feast on Nov. 30 and Orthodox delegates visiting Rome for the feast of Sts. Peter and Paul on June 29.

Koch led this year’s Vatican delegation. He was accompanied by Archbishop Flavio Pace, Secretary of the Dicastery; Monsignor Andrea Palmieri, Undersecretary; and Archbishop Marek Solczyński, Apostolic Nuncio to Turkey.

The delegation participated in the Divine Liturgy at the Patriarchal Church of St. George, Phanar, and held discussions with the synodal commission charged with relations with the Catholic Church.