Pope Benedict XVI is due to meet Archbishop of Canterbury Rowan Williams, leader of the Church of England and spiritual head of the Anglican Communion, during his four-day visit to England and Scotland.
King Henry VIII of England broke with Rome and set himself up as supreme governor of the new Church in 1534, paving the way for centuries of tension between London and the Vatican. Relations have improved markedly in the past half century, but the pope's trip coincides with a period of renewed problems.
Here is a chronology of major events in the rapprochement between the two Churches over the past 50 years.
1962 -- The Second Vatican Council opens under the auspices of Pope John XXIII and ushers in an air of reform including the start of dialogue with other faiths.
1966 -- Michael Ramsey becomes the first archbishop of Canterbury in modern times to formally visit the Vatican. As a sign of the warm relationship that emerged, Pope Paul VI gave his papal ring to Ramsey, who wears it until his death. Since then, it has been worn by archbishops when visiting the Vatican.
1967 -- The first meetings take place to form the Anglican-Roman Catholic International Commission (ARCIC), which seeks to make ecumenical progress between the two churches. It has worked in two phases, in 1970-1981 and 1983-2005.
1975 -- Pope Paul VI writes to Archbishop of Canterbury Donald Coggan, a supporter of women priests, saying women cannot be ordained because Christ's Apostles were all men.
1977 -- Archbishop Coggan makes an unexpected gesture and calls for full intercommunion between the Anglican Communion and the Roman Catholic Church during a visit to Rome.
1982 -- Pope John Paul II becomes the first pontiff to visit Britain, attracting hundreds of thousands of followers. He visits Canterbury Cathedral and he and Archbishop of Canterbury Robert Runcie pray at the site where Archbishop Thomas Becket was martyred in 1170 by followers of King Henry II after he changed his allegiance from the king to the pope and the Church.
1992 -- The Church of England (CofE) General Synod approves the ordination of women priests. The first takes place in 1994.
2003 -- Relations stumble after the consecration of Gene Robinson as the first openly gay bishop in the Episcopal Church of the United States and the wider Anglican Communion.
2005 -- The CofE General Synod votes to start removing legal obstacles to the ordination of women to the episcopate.
2006 -- Archbishop of Canterbury Rowan Williams visits Pope Benedict in Rome. Their joint declaration affirms their continued commitment to seek unity and common purpose, including "promoting respect for life from conception until natural death; protecting the sanctity of marriage and the well-being of children in the context of healthy family life."
2009 -- Apparently good relations between Benedict and Williams are soured by a Vatican Apostolic Constitution making it easier for disaffected Anglicans to convert to Catholicism while retaining some of their traditions. Both churches say the offer will not affect dialogue, but Anglicans are convinced Williams was humiliated by a lack of advance warning. How many Anglicans would convert remains unclear.
2010 -- July 9-12 -- The CofE General Synod approves the latest stage in the consecration of women bishops, a long process unlikely to be completed before 2014. Within days, the Vatican codifies the "attempted ordination of a woman" to the priesthood as a most serious crime against Church law.
2010 -- September 16-19 -- Pope Benedict makes the first state papal visit to Britain.
(Sources: The Archbishop of Canterbury official website, RC Archdiocese of Southwark website, the Vatican website, Church of England, Bishops' Conference of England and Wales, the Anglican Communion, Canterbury Cathedral)
(Writing by Avril Ormsby; Editing by Tom Heneghan and Mark Heinrich)