Archbishop of Canterbury Rowan Williams, spiritual leader of the world's Anglicans, will make his first official visit to Pope Benedict at the Vatican on 23 November.

The timing is significant because this year marks the 40th anniversary of the historic meeting between his predecessor, Archbishop Michael Ramsey, and Pope Paul VI in 1966.

That was the first formal meeting between the heads of the two churches since England's King Henry VIII broke with Rome in the 16th Century.

In the past 10 years, relations between the two Churches have been strained over the issue of women priests and homosexual bishops.

The blessing of same-sex unions in Canada's Anglican Church and moves to ordain women bishops in the Church of England are two issues that are driving Anglicans and Catholics further apart after decades of optimistic dialogue.