The Week was conceived in 1908 by the Franciscan Friars and Sisters of the Atonement at the Graymoor church center in Garrison, New York. They celebrated the Church Unity Octave between the Feasts of Saint Peter (January 18) and Saint Paul (January 25). The Week slowly grew in popularity as it was adopted by local interchurch prayer groups and monastic communities. By 1926, the Faith and Order movement was publishing its “Suggestions for an Octave of Prayer for Christian Unity.”

The formation of larger ecumenical bodies, such as the World Council of Churches, encouraged the spread of the Week in both large gatherings and local churches. In 1966, as an expression of unity, the Joint Working Group between the World Council of Churches and the Roman Catholic Church agreed to jointly prepare materials for the Week. To promote the global nature of Christian unity, the materials starting in 1975 were drafted with consultation from local ecumenical groups, such as regional ecumenical organizations and national and state councils of churches. Each year, Christians globally pray alongside the churches in that region as they learn of their struggles and witness.

Here, in the United States, the Week often coincides with the national observance of Martin Luther King Jr. Day on the third Monday of January. The timing draws attention to the racial divisions among Christian churches, and churches are reminded of their high calling of unity by the life and witness of Dr. King, one of the foremost figures in the history of American ecumenism. The Week is also part of the year-long Ecumenical Prayer Cycle, through which Christians pray for churches around the world.

For more information on the Week and the annual theme, please visit the pages of the World Council of Churches in English and Spanish. The Graymoor Ecumenical and Interreligious Institute offers resources for those planning celebrations, including guidance on organizing collaborative events, bulletin designs, posters, and prayer cards in English and Spanish.