The Archbishop of Canterbury Rowan Williams will step down at the end of the year.
Williams, who spent 10 years in the post, has announced that he will take up a new post as Master of Magdalene College, Cambridge.
The Queen, as Supreme Governer of the Church of England, has been informed of Williams decision to leave the position, which he claimed has been an "immense privilege", while moving on has "not been an easy decision".
"During the time remaining there is much to do and I ask your prayers and support in this period and beyond. I am abidingly grateful to all those friends and colleagues who have so generously supported Jane and myself in these years and all the many diverse parishes and communitites in the Church of England and the wider Anglican Communion that have brought vision, hope and excitement to my own ministry.
"I look foward, with that same support and inspiration, to continuing to serve the church's mission and witness as best I can in the years ahead."
Williams, 61, will continue to carry out all of the duties of the 104th archbiship for the Church of England and Anglican Communion, which he undertook in December 2002, until the end of the year before starting his new role in January. His successor will then be selected by the Crown Nominations Commission.
In his time as archbishop, Williams marked himself out as an outspoken and occasionally polarising figure, although he told the Press Association that he did not feel as if he was "free at last" in stepping away from a role where every public proclamation draw great scutiny.
The rights of homosexuals in the eyes of the church has been an ever present debate point for Williams. He has commented that the church should be "welcoming" while not "inclusive", a position that appears to tread an ever-narrowing line. As momentum builds behind same-sex marriages, Williams made it clear that the law should not be used as a tool to bring about social change. He told the Telegraph that the issue should be addressed through "culture rather than law".
With regard to gay bishops, he claimed that the church had no problem with their status, but was not positive about them having relationships, as it "the scriptural and traditional approach to this doesn't give much ground for being positive about it."
Williams courted controversy in February 2008 when he discussed Sharia Law, claiming that its adoption "seems unavoidable".
Speaking to World at One on Radio 4, Williams claimed that it would be a "danger" to have an approach to law that said "there's one law for everybody and that's all there is to be said".
The argument over the teaching of creationism in schools, although lacking the intensity of debates in the US, was brought to Williams with regard to its teaching in privately sponsored academies.
Williams marked himself out as a believer that the church and the theory of evolution should not be considered mutually exclusive.
Conflict and the War on Terror
Williams has never been shy of criticising the government for its military actions, publically signing petitions against the Iraq War and writing to then prime minister Tony Blair criticising the conduct of troops in Iraq.
He maintained an attitude of support for the UK's Muslim community, speaking out against attacks based on religion. He criticised the decision by Nicolas Sarkozy to ban the wearing of the hijab in France, claiming no religious symbols should be outlawed.
Williams' departure comes as the Church of England General Synod is on the cusp of approving the introduction of female bishops, something he claimed was one of the most significant legislative decisions it has had to make in the last 20 years.
In November 2010 he said: "[Female bishops are] something I would like to see, yes, and its something which I think a majority of people in the Church of England would be very happy with.
"But I alse share the concerns of a lot of people who have convictions about the ruightness of women bishoips, so we have got to be loyal to these people who want to be loyal to us, and make the best provision we can."
Williams was consecrated bishop of Monmouth in 1991 and elected archbishop of Wales in 1999