Andrew Strauss says he is standing down as England's director of cricket as his wife battles cancer.
The former opening batsman took a break from his position at the start of the summer after his wife Ruth began a new course of treatment.
In a statement, Strauss said he had taken the "difficult decision" to step down as England prepares to host a World Cup and Ashes series next year.
"Taking time out this summer to support my wife and kids, as Ruth goes through treatment for cancer, has given me the chance to fully consider what's right for England and what's needed at home," he said.
"The role in cricket requires total focus and commitment to deliver the best results, yet right now I need far more flexibility than could ever be possible in my position in order to support my family."
Strauss, who has been in his post since May 2015, will initially help the England and Wales Cricket Board (ECB) prepare to appoint his replacement.
Andy Flower, who has been standing in on an interim basis, will continue in the role until December, when a successor is likely to be named.
Strauss, who retired from cricket in 2011 with 100 Test caps to his name, became director of England cricket in 2015.
He immediately took some hard decisions, including the sacking of head coach Peter Moores and, most controversially, rubber-stamping the end of Kevin Pietersen's England career.