The Archbishop of Canterbury will leave office on Monday after a decade as head of the Church of England and spiritual leader of the 77 million-strong Anglican Communion.
Dr Rowan Williams, 62, departs as the 104th Archbishop of Canterbury to take up the posts of Master of Magdalene College Cambridge and chairman of the board of trustees of Christian Aid, the international development agency.
He will be replaced by 56-year-old former oil executive the Rt Rev Justin Welby, the Bishop of Durham, who will be consecrated in March at Canterbury Cathedral as Archbishop of Canterbury.
Dr Williams's departure comes after a turbulent 10 years in office in which he has fought to maintain unity within the Anglican Communion amid rows over Church teaching on gay relationships.
He leaves the Church of England battling to resolve long-running negotiations over the introduction of women bishops after legislation to introduce the first female bishops was defeated last month at the General Synod.
The Archbishop's decade in office has also featured high-profile interventions on controversial issues such as the invasion of Iraq, sharia law and government economic policy.
He has been willing to take part in public debates with leading atheists and critics of the Church such as Professor Richard Dawkins and the author Philip Pullman.
Delivering his final Christmas Day sermon from Canterbury Cathedral, Dr Williams spoke of how he has been inspired by meeting people who have experienced great suffering, such as victims of gang violence.
He also acknowledged that the General Synod's vote against allowing women to become bishops had damaged the credibility of the Church.
But he pointed out a reason to be positive - the recently-published Census statistics indicated that 59% of people still identified themselves as Christian.