The Bishop of Lincoln has said he is praying for the recovery of the Archbishop of York, who underwent surgery today for a locally advanced cancer of the prostate.
Dr John Sentamu was treated today at St James' Hospital Leeds and said he would "be out of action for some time".
Bishop Christopher Lowson said he was "saddened" by news of the Archbishop's illness and the expectation he would be recovering for some time.
The bishop gave his assurances that he and others in the diocese would be praying for the Archbishop.
"Knowing the Archbishop as a man of great energy and passion, I know that this enforced rest will not come easily to him," he said.
"I and the Diocese of Lincoln join the Church in holding Archbishop John and his family in our prayers, and wish him a speedy and complete recovery."
There has been an outpouring of sympathy on Twitter for the Archbishop since the announcement was made late this afternoon.
Churches Together in York, Dan Jarvis MP and Bishop Graham Kings were among those tweeting their concern.
"My thoughts are with the indefatigable @JohnSentamu," tweeted Jarvis.