Simon Case: Who is the government's new top civil servant?

Simon Case has been appointed cabinet secretary and head of the civil service - and thus takes on the unofficial title of the most important man in politics you've probably never heard of.

The cabinet secretary is the top job in the civil service and involves advising the prime minister, leading implementation of the government's policies and managing other high-level civil servants.

Despite the power they wield, cabinet secretaries, unlike ministers, usually stay behind the scenes and rarely give public interviews.

• Simon Case confirmed as UK's top civil servant

• UK's top civil servant announces exit

• What tasks lie ahead on the return to Westminster?

Born in Bristol in 1978, Mr Case attended Bristol Grammar School, an independent school which boasts comedian Mark Watson and Darth Vader actor David Prowse among its alumni.

He attended Trinity College Cambridge where he studied history and went on to complete a PhD in political history at Queen Mary University London.

His thesis - the Joint Intelligence Committee and the German Question, 1947-61 - looked at how assessment from that committee informed government policy during the Cold War.

In 2006, he joined the civil service as a Ministry of Defence policy adviser.

Simon Case was involved in arrangements for the 2012 London Olympics

Over the next eight years he held roles in the Cabinet Office, the Northern Ireland Office, GCHQ and on the Olympic Secretariat - which was involved in overseeing the 2012 Olympic Games in London.

In 2012 he became private secretary to then-Prime Minister David Cameron.

After a stint in the Cabinet Office's Implementation Group, he returned to No 10 and has worked as principal private secretary to the PM.

In recent years he has taken on roles in tricky areas.

He was part of the team involved in the Brexit talks but left in 2018 to become Prince William's private secretary - a job which left him negotiating a very different exit as Prince Harry and his wife Meghan sought to step back from life as senior royals.

Simon Case worked as private secretary to Prince William at a particularly turbulent time

Earlier this year Mr Case again returned to No 10, this time to help with the government's coronavirus response.

According to Who's Who he is a member of the Garrick and Hawks' clubs and his hobbies include cycling, rowing, running and swimming.

• What do the UK's 450,000 civil servants actually do?

• Minister takes aim at civil service 'group think'

His predecessor Gus O'Donnell, cabinet secretary from 2005-2011, told the BBC it is "a surprise to have someone so young" in the role, but added that the new top civil servant had plenty of Downing Street experience, adding, "I'm sure he will grow into the role."

He also said Mr Case "knows how to make things happen" and had "clearly developed the trust of the prime minister".

Lord O'Donnell said one of his task would be getting Boris Johnson to "understand he needs to work with the civil service rather than against them".

Mr Case's appointment comes at a time when the government is seeking to shake up the civil service with senior advisor Dominic Cummings warning of a "hard rain".

Former Treasury permanent secretary Nick Macpherson described Mr Case as "a sound man and a good appointment" adding "he knows a thing or two about Whitehall".

Simon Case now takes on a pivotal role in the civil service at a time of very significant change.

The government is very keen to do pretty sweeping reforms as far as the civil service is concerned.

We've seen several permanent secretaries, and the cabinet secretary no longer in the roles they were previously in.

This is a sign of that change.

It is also a sign that it is not just police officers who are looking younger.

He is the most senior civil servant in the country and he is just 41-years-old.