(Britain's Archbishop of Canterbury Rowan Williams (R) and his wife Jane wave to Queen Elizabeth and Prince Philip after a Diamond Jubilee multi-faith reception at Lambeth Palace in central London February 15, 2012. )

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.