Pope Francis receives a 'Simnel Sunday' cake during his visit to Rome's All Saints Anglican Church (26 Feb. 2017). Photo credit: ANSA

Pope Francis passes in front of an icon of Jesus Christ during his visit at the All Saints' Anglican Church in Rome (26 Feb. 2017). Photo credit: AFP

Pope Francis delivers a joint blessing with Orthodox Metropolitan Gennadios of Italy and Malta and Anglican Archbishop David Moxon, the archbishop of Canterbury's representative to the Vatican, during an ecumenical prayer service to conclude the Week of Prayer for Christian Unity at the Basilica of St. Paul Outside the Walls in Rome (25 Jan. 2017). Photo credit: Paul Haring/CNS

In this 2017 file photo, Pope Francis is flanked by Archbishop David Moxon, then the archbishop of Canterbury's representative to the Vatican, and Cardinal Kurt Koch, president of the Pontifical Council for Promoting Christian Unity, as they arrive for an ecumenical prayer service to conclude the Week of Prayer for Christian Unity at the Basilica of St. Paul Outside the Walls in Rome (25 Jan. 2017). Photo credit: Paul Haring/CNS

Christians united: the Archbishop of Canterbury greets the Archbishop of Westminster, Cardinal Vincent Nichols (2017)

The Archbishops of Canterbury and Westminster are “the closest of friends”, Justin Welby has said in an article for London’s Evening Standard newspaper; but the Protestant Reformation has damaged communion between Christians in ways which are still not healed, 500 years on (2017). Photo credit: Lambeth Palace