It is not always remembered that the one-hundred-and-two-year-old Week of Prayer for Christian Unity is thoroughly Catholic in origin and conception. Even its antecedents in the 19th century were inspired by a shared vision of the integrity of Christ's one Church and the desire for fulness of communion in the Spirit, proclamation of the Word of God, the order of the Church which serves and embodies that, and in sacramental and eucharistic life.
It began its existence as the Church Unity Octave in 1908, founded by Anglicans after a decade of despondency about the adverse judgment of the Roman See about Anglican Orders, just as Anglican leaders were beginning to look more to closer links with Christians in Reformed and Evangelical churches. Fr Paul Wattson, an American Epsicopalian Franciscan friar, and the Revd Spencer Jones, vicar of Moreton-in-Marsh and the author of the book, England and the Holy See, which caused a great national debate, combined to set up the Octave with a reminder to their fellow Anglicans that Church unity could never be piecemeal or simply be a partial union between the like-minded, but had to start from the first principle of the integrity of the whole of Christ's Church as already one. Thus the reunion of all Christians with the Apostolic See of Rome and the successor of Peter, its Bishop, the Pope, was not merely a distant aspiration because of present difficulties and disagreements, the last step in ecumenism, but actually its first step. Unless the step was made in this direction from the outset, no one could ever arrive at it as the last.
The famous 1910 Edinburgh Mission Conference, to which the Catholic Church was invited to send representatives but declined to attend because the Conference seemed to promote the belief that there could be many parallel churches rather than one in which all could find unity, seemed to encourage the idea of an all-embracing fellowship of churches arising from the Reformation tradition, but maintaining their different theologies and systems. Jones felt that this movement was driving the Church of England from its Catholic self-understanding and the principle of reunion and reconciliation in one Church. He was central to the circle of figures that brought about the foundation of the Catholic League in 1913 to work for the union of all Christians in the Catholic faith and in union with the Apostolic See of Rome.
In 1908, Fr Wattson and his fellow friars were received as a community into the Catholic Church as the Society of the Atonement, which is still active in north America as a force promoting Catholic ecumenism. Wattson and Jones remained in contact as friends, both working and hoping for the same ideal of unity in Catholic faith and order. Meanwhile, the Church Unity Octave was sanctioned by Pope Pius X in 1909 and in 1916 extended to the whole Catholic Church by Pope Benedict XV as an aid for prayer and reconciliation among the nations at the height of the disastrous World War I. This was on top of a long-standing convention of praying between Ascension and Pentecost for the Reunion of Christians, especially between Anglicans and Catholics, established in 1894 by Archbishop Edward Benson of Canterbury and by Pope Leo XIII in 1897.
The Church Unity Octave itself, as a Roman Catholic devotion, was not widely adopted beyond certain Roman Catholic and pro-papal Anglican circles. Yet a growing understanding of shared Christian identity, dogmatic belief and unitedness in the Scriptures that followed the Great War, together with the renewal from the Litrugical Movement and growing western awareness of Eastern Christianity on account of the many thousands of Orthodox and Byzantine Catholic refugees from communist and famine-struck Soviet Russia, revealed that Orthodox, Protestant and Anglican Christians continued, after all, to share a hope for unity in the one Body of Christ. Dom Lambert Beauduin, founder of the monastery that is now at Chevetogne in Belgium, was a pioneer in an ecumenically-aware monasticism that continues to this day to pray for unity through study, dialogue and the celebration of the Church's litrugy from both east and west. This in turn had a profound influence on Fr Paul Couturier, a teacher-priest from Lyon who thereafter devoted his every spare waking moment to enabling encounter between Christians of all traditions, and even people of other faiths, in what he called the "invisible monastery" of heaven, high beyond the walls of earthly separation, united there, if not on earth, in prayer for the unity and sanctification of all humanity in the charity and truth of Christ. Thus he added on to the Church Unity Octave the means for other Christians to unite themselves with the prayers of Catholics for the same hope of unity, "according to Christ's will, according to his means". The "spiritual ecumenism" which he commended became a cornerstone of the Vatican II Decree on Ecumenism, Unitatis Redintegratio.
The renewal of the Church Unity Octave so as to make it possible for Orthodox, Protestants and Anglicans to offer prayers in the same week for Christian Unity, without any hint of urging anyone to be disloyal to their Church or Communion's teaching or to compromise on their theological principle, was motivated from beginning to end with prayer for one's own and one another's ever greater holiness and faithfulness in Christ. The spiritual principle was that the more closely one came to union with Christ, the closer one draws to fellow Christians on their own, similar journey; and thus can the churches draw closer to one another through entering more deeply into the truth, repenting of past mutual wrongdoing and rivalry, returning to theological and spiritual sources so as to retrace steps side by side on a common journey towards reconciliation in the same faith. Couturier called this common spiritual endeavour augmenting what was now named the Chair of Unity Octave (to stress the abiding centrality of the communion of all the churches with the See of Peter - it is noteworthy that that the new American Ordinariate for Catholics with an Anglican patrimony is established as the Ordinariate of the Chair of St Peter, making clear its fundamentally ecumenical mission), "the Week of Universal Prayer for the Unity of Christians".
The spiritual involvement in the Octave, the Week of Prayer, became very widespread. It took on a new lease of life as the World Council of Churches was established as a new world order took shape after the Second World War and Christians were looked to for promoting principles of justice, peace and unity in humanity. The Faith and Order Commission is nowadays a principal agency by which the World Council of Churches and the Catholic Church internationally collaborate towards unity. From the 1950s it was producing spiritual resources for prayer for unity as commended by Fr Paul Couturier. In 1966 the two Catholic approaches - the Wattson's Chair of Unity Octave and Couturier's supplemental Week of Prayer - were formally united and from the following year the WCC and the Secretariat for Promoting Christian Unity (now a Pontifical Council) have produced annual materials for the Week of Prayer jointly through Faith & Order.
In 2003, the League arranged a celebration to mark the 70th Anniversary of the Refounding of the Week of Prayer and the 50th Anniversary of Fr Paul Couturier's death. In 2008 a great celebration of the Centenary of the Week of Prayer from its foundation as the Church Unity Octave was held in Westminster Abbey, led by Archbishop Rowan Williams and Cardinal Cormac Murphy O'Connor. More details on the history and significance of the Week of Prayer can be found on the League's dedicated websites:
download here, from the League's Members' Secretary and Priest Director of the Apostleship of Prayer (email here) or from St Paul's Bookshop by Westminster Cathedral.