[1][2] After he was diagnosed with lung cancer,[3] he took a leave of absence from June 2018, and retired on health grounds on 24 October 2018, receiving a life peerage; he died a fortnight later on 4 November 2018.

[4] His parents were Peter Heywood and Brenda Swinbank,[5][6][7] who met as teachers at Ackworth School in West Yorkshire, one of a few Quaker educational establishments in England.

[8] He studied history and economics at Hertford College, Oxford (where he was later made an Honorary Fellow), graduating with a Bachelor of Arts (BA) degree in 1983.

[4] From 1983 to 1984, Heywood worked as an economist at the Health and Safety Executive, before moving to the Treasury,[10] and became the Principal Private Secretary to the Chancellor of the Exchequer, then Norman Lamont, at the age of 30, having to help mitigate the fallout from Black Wednesday after less than a month in the job.

[16] On 11 October 2011 it was announced that Heywood would replace Sir Gus O'Donnell as the Cabinet Secretary, the highest-ranked official in Her Majesty's Civil Service, upon the latter's retirement in January 2012.

It was also announced that Heywood would not concurrently hold the roles of Head of the Home Civil Service and Permanent Secretary for the Cabinet Office, as would usually be the case.

[10] He was criticised when he vetoed the release to the Chilcot Inquiry of 150 letters and records of phone calls between Tony Blair and President George W. Bush before the 2003 Iraq War.

Heywood was found to be primarily responsible for businessman Lex Greensill being given a role in government and "extraordinarily privileged" access into 10 Downing Street.

[4] Cook, who became a CBE in the King's Birthday Honours in 2024, is a former civil servant who moved into the private sector: she has been managing director of the Exor Group since 2016 and chair of CNH Industrial since 2018.