The Archbishop of Canterbury will meet Pope Francis for the third time next week to celebrate 50 years since an Anglican Centre was founded in Rome aiming to "promote Christian unity in a divided world".
The week-long summit in Rome will climax with a service in the monastery from which St Augustine was sent to evangelise Britain in 597 AD. At the service 19 pairs of Anglican and Roman Catholic bishops will be commissioned to work together in "joint mission".
Justin Welby and Pope Francis have met twice before after being installed within a week of each other in 2013.
The bishops will take part in a simultaneous summit that starts in Canterbury on Friday before they travel to Rome on Monday to join Justin Welby and Pope Francis. Before they leave the UK the 36 bishops, representing 19 regions around the world, will visit the shrine of St Thomas a Beckett where Pope John Paul II and Archbishop Robert Runcie historically prayed together in 1982.
The highly symbolic programme is designed to highlight closer ties between two Churches that spent centuries in conflict. "It is an immensely significant occasion," said Bishop David Hamid, co-chair of International Anglican Roman Catholic Commission on Unity and Mission (IARCCUM), which chose the bishops. He said there had been "extraordinary progress" between the two churches in the last 50 years.
"The common faith we have discovered through our years of dialogue now compels us to act together, sharing in Christ's mission in the world," he said.
A spokesman from Lambeth Palace told Christian Today the bishops' commissioning "recognised Catholics and Anglicans can do a lot together locally in terms of mission".
The Anglican Centre in Rome was established in 1966 after a meeting between Archbishop Michael Ramsey and Pope Paul VI where the Pope gave Ramsey his papal ring. Welby will wear the same ring during the visit.
The Director of the Anglican centre, Archbishop David Moxon, hailed the celebration as a "new chapter in the history of the Christian Church".
He said: "The Anglican Centre has worked for fifty years to help Roman Catholics and Anglicans work together, pray together, study and talk together.
"The journey we are on demands the laying-down of old fears and misconceptions of each other, and the building up of a shared story together."
Welby recently joked that Pope Francis would beat him in a fight
"For a lot of reasons, the Pope would (win)," he said in response to a child's question at Greenbelt Festival. "He's got a bigger stick than me. He's got a bigger hat then me. He's bigger then me. He's better than me."
