Now known as the Week of Prayer for Christian Unity, with its original meaning removed after the Council, starts today.
Antiphon That they all may be one, as thou, Father, art in me and I in thee; that they also may be one in us; that the world may believe that thou hast sent me.
V I say unto thee that thou art Peter
R And upon this rock I will build my Church.
Collect O Lord Jesus Christ, who saidst to thine apostles Peace I leave with you, my peace I give unto you: regard not our sins but the faith of thy Church; and grant to her peace and unity according to thy will; who livest and reignest with the Father and the Holy Ghost, ever one God, world without end.
This is the form of prayer used through the first sixty years of the twentieth century by Anglo-Papalists, and commended by their organisations. When Ecumenism became broadened (and diluted??), it tended to fall out of use.
The first day of the Unity Octave, being the celebration of S Peter's Chair at Rome, is something we owe to Pope Paul IV, acting in 1558 ... the very year when Bessy Tudor's cronies were plotting a new rupture with Rome. Paul IV was not, actually, a very nice man, and did a fair bit of No Good to the English Catholic Church ... he wanted to try our own dear Cardinal Pole for heresy ... but, well, these coincidences in dates are rather intriguing, aren't they?
After the Chair of Unity Octave mutated into the Week of Prayer for Christian Unity, each day in the Week was assigned to prayer for particular Christian traditions. These intentions differed from time to time. As for me, I think I may pray especially this year for Unity within the canonical borders of the One Fold of the Redeemer: that more and more Catholics may escape from the narrow, grim, frowning, focus upon hatred, and discover the generous and beautiful breadth and depth of Holy Tradition.
*I have adjusted the translation of the Collect to the text of the Ordinariate Missal, which is actually the precise wording of the Devotion as offered for use in the first Walsingham Pilgrims' Manual, suggesting that it be said outside the Slipper Chapel by our forefathers as they stood there praying God to bring them into Unity.