LONDON Archbishop of Canterbury Rowan Williams, well-liked within the Anglican Communion but often an irritant to the British government, has struggled with the two issues that have dominated the religious agenda: gay bishops and same-sex unions.
After announcing his resignation from a turbulent church, he will probably return to the gentler world of academia a worn man after a decade of wrestling with the near-impossible task of reconciling traditionalists and liberals within the 80-million strong Anglican Communion.
Seen as a bookish theologian, Williams tried to define Anglican positions more clearly and strengthen his central role.
Unlike Roman Catholicism, Anglicanism is a loose grouping of churches whose head has no direct power over all members.
Considered a liberal when he became archbishop in 2002, he constantly sacrificed his private beliefs to maintain the unity of the Church.
But the poet and linguist increasingly struck a forlorn figure, suffering a series of blows to his personal authority by the unyielding factions.
The only Welshman to hold such office, he failed to deliver on what liberals wanted while also falling short of traditionalist demands.
The 61-year-old will leave at the end of the year, about a decade earlier than the normal retirement age for bishops, with his gentle humor still intact but his energy likely sapped.
A royalist who conducted the wedding of Prince William and Catherine Middleton last April, Williams will stay in place for Queen Elizabeth's diamond jubilee this year, marking her 60 years on the throne.
And Britain's most senior cleric will also see through a busy year for the Church of England with its parliament, or General Synod, set to vote in July on the consecration of women bishops, and a landmark Anglican agreement called the Covenant.
It is the likely outcome of these two votes that has pushed Williams to step down after having invested so much personal authority in them, though he gave no reason in his resignation statement.
Williams' tenure has come at a time when the worldwide Anglican federation of 38 churches threatens to tear itself apart in doctrinal disputes over homosexuality and the role of women.
He has sought to hold the Anglican community together by urging them to adopt an agreement, or covenant, aimed at preventing disputes largely between churches in North America and Africa over gay bishops and same-sex unions by offering more central authority.
Despite several Anglican churches abroad having accepted it, the Church of England dioceses, or parishes, look set to vote it down.
This would be a major blow for Williams who pushed for such a covenant following tensions over the consecration of an openly gay bishop at the Episcopal Church, the official U.S. member of the Communion.
Those Anglicans who supported the consecration of Bishop Gene Robinson fear the covenant would impede similar acts in future.
TENSIONS WITH ROMAN CATHOLIC CHURCH
Williams has also tried to reach an agreement on women bishops in the Church of England in an attempt to prevent traditionalist Anglo-Catholics and evangelicals leaving.
About 50 traditionalist priests have already taken up an offer by Pope Benedict to switch to Rome within a so-called ordinariate which allows them to keep some of their traditions, and others are likely to follow if they lose.
Williams suggested a compromise at synod in February, following an earlier embarrassing defeat. The compromise is currently with the House of Bishops.
As the Anglican Communion moves towards more liberal measures, its relations with the Roman Catholic Church have also cooled, despite seemingly warm personal relations between Williams and the pope.
Benedict's offer of an ordinariate caused tension, with many feeling the announcement had been handled badly, sidelining Williams.
Relations appeared to have been smoothed with the pope's visit to England and Scotland in September 2010.
Williams found himself out of step with different British governments over the years, as well as the popular press.
He caused uproar in 2008 when he said the introduction of some aspects of Islamic law in Britain was unavoidable. Britain's biggest selling daily tabloid, The Sun, launched a campaign for him to quit.
More recently, he made an outspoken attack on the coalition government, accusing it of causing anxiety and fear with "radical, long-term policies for which no one voted", eliciting a robust response from Prime Minister David Cameron.
Church leaders are also currently battling the Conservative-led coalition government over its plans to allow same-sex marriage in an increasingly secular society.
During the financial crisis in 2008, he came to blows with then Labor Prime Minister Gordon Brown after he criticized the government's fiscal stimulus package, likening it to "an addict returning to a drug".