Early History of the Week of Prayer for Christian Unity

In 1913, the Faith and Order Commission of the Protestant Episcopal Church published a leaflet promoting prayer for unity on Whitsunday and in 1915 published a Manual of Prayer for Unity. The preparatory Conference on Faith and Order at Geneva in 1920 appealed for a special week of prayer for Christian unity ending with Whitsunday. Faith and Order continued to issue “Suggestions for an Octave of Prayer for Christian Unity” until 1941 when it changed the dates for its week to that of the January Octave. In this way, Christians, who for reasons of conscience, could not join with others in prayer services could share in united prayer at the same time. These various efforts while not attaining wide observance among the churches was to pave the way for the Week of Prayer for Christian Unity which came to be observed widely throughout Christendom.

Source: Rev. Thomas Orians, S.A. - "BACKGROUND: Brief History of the Week of Prayer for Christian Unity 2017", by Rev. Thomas Orians, S.A., Associate Director of Graymoor Ecumenical & Interreligious Institute, http://geii.org/week_of_prayer_for_christian_unity/background/brief_history.html