Prime minister David Cameron praises Dr Rowan Williams, who has announced his resignation as Archbishop of Canterbury:
"I would like to thank Rowan Williams for his dedicated service as Archbishop of Canterbury.
"As a man of great learning and humility he guided the church through times of challenge and change.
"He sought to unite different communities and offer a profoundly humane sense of moral leadership that was respected by people of all faiths and none.
"As prime minister, I have been grateful for his support and advice - and for the work he has done around the world, particularly in Africa where he has taken such a close interest in Sudan.
"I wish Rowan and his family the very best for the future."