First female director of GCHQ appointed
Anne Keast Butler will take over when Sir Jeremy Flemming steps down in May.
A woman will become the boss of GCHQ for the first time in its more than 100 year history.
Anne Keast Butler will take over as the director of the Government's Cheltenham based communications headquarters when Sir Jeremy Flemming steps down in May.
Ms Keast Butler is currently MI5's deputy director general and is said to be "delighted" at her appointment.
"I was privileged to work in GCHQ a few years ago, so I know I am again joining a world-class team of people from diverse backgrounds with a broad range of skills, who share a singular focus on making our country safer, more secure, and more prosperous," she said.
"I am passionate about continuing to ensure that GCHQ is an organisation where everyone can perform to their very best.
"I am so grateful for the vision and dedication Sir Jeremy Fleming has shown during his tenure, and the ways in which GCHQ has transformed under his leadership.
"I look forward to building on this in the months and years to come. I can't wait to get started."
Ms Keast-Butler has spent 30 years working in national security.
Before holding senior security service roles at MI5, she spent two years on secondment to GCHQ as head of counter-terrorism and serious organised crime, and also worked in Whitehall over the last decade, during which time she helped launch the National Cyber Security Programme.
Sir Jeremy said: "Anne's appointment is fantastic news for the organisation. I have worked with Anne for decades and think she is a brilliant choice with deep experience of intelligence and security in today's technology-driven world."
Mr Cleverly said: "Anne Keast-Butler has an impressive track record at the heart of the UK's national security network, helping to counter threats posed by terrorists, cyber-criminals and malign foreign powers.
"She is the ideal candidate to lead GCHQ, and Anne will use her vast experience to help keep the British public safe."
National Security Adviser Sir Tim Barrow said Ms Keast-Butler was an "exceptional candidate in a talented field" and thanked Sir Jeremy for his service, adding: "Jeremy's insights and analysis have been hugely valuable through one of the most demanding periods of our recent history."