The Archbishop of Canterbury's head of staff, the Bishop at Lambeth, is stepping down in August.
Rt Rev Nigel Stock retires as Justin Welby's clerical aide and advisor after nearly four years in the job as well as from his position as Bishop to the Forces and Bishop to the Falkland Islands.
The post means Stock has overseen the Archbishop's engagement with the sexuality report in the House of Bishops and the General Synod as well as advising Welby on his wider strategy and inter-church relations.
A successor will be announced in April.
Stock said it had been a 'privilege' to work with Welby.
'Among many highlights it was wonderful to accompany the Archbishop in ground-breaking visits to His Holiness Pope Francis,' he said.
'There are crucial events in the not too distant future, not least the Lambeth Conference 2020. I know the Archbishop will continue to bring his boundless energy and vision to both the Church of England and the Anglican Communion and I remain hugely grateful that he has been called to be Archbishop for this time.
'I am particularly grateful for the Archbishop's very clear message about the transformation to life that occurs when a person encounters Jesus Christ. I believe that that gift of Christ will always bring hope to any person in any nation. I am confident that all the initiatives in evangelism will evoke a response from many people.'
Thanking him, Welby said: 'I am enormously grateful to Bishop Nigel for his years of service here at Lambeth. His love for and service to the Church of England and the Anglican Communion have been a blessing and an inspiration, not just to me but to all of us at Lambeth Palace.
'He has been a gracious and wise friend, and he and Carolyne have contributed enormously to the community of communities at Lambeth.
'His wisdom is hugely valued and he has an unshakable calm and clarity of thought which he brings to often very complex situations. His profound spirituality has led us all closer to Christ.
'We will miss all that he has brought to the role and we pray for him and his family as he enters the next phase of his life.'
