[3] Frequently pictured posing by the famous Number 10 front door, Humphrey's primary duties involved catching mice and rats in the maze of Downing Street buildings.

[5] In November 1993, an internal memo was circulated in the Cabinet Office informing staff that Humphrey was suffering from a minor kidney complaint and had been put on a special diet.

[6] Humphrey was accused on 7 June 1994 of having killed four robin chicks which were nesting in a window box outside the office of John Major, then Prime Minister.

[10] The publicity led to his rediscovery in the nearby Royal Army Medical College, where he had been taken in as a presumed stray and renamed PC, short for "patrol cat".

[11] Upon his return, Humphrey issued a statement through the civil service: "I have had a wonderful holiday at the Royal Army Medical College, but it is nice to be back and I am looking forward to the new parliamentary session.

In November 1997, Humphrey's primary carer, Jonathan Rees, who worked in the Prime Minister's Policy Unit, wrote a memo stating that the cat should retire to a "stable home environment where he can be looked after properly".

[3] Humphrey moved to his new home with an elderly couple in suburban London on 13 November 1997, though his retirement was not announced until the next day to reduce the risk of kidnap attempts.

In March 2006, a spokesman for Tony Blair reported that Humphrey had died during the previous week, at the home of the Cabinet Office worker who had been accommodating him.

[21] Humphrey also appeared in the political satire Spitting Image, portrayed as a cat who would irritate John Major by criticising the government.