November 3, 2025

A Century of Chief Mousers: The Cats Who Ruled 10 Downing Street

From Rufus in 1929 to Larry the cat today, here's the story of Britain’s most famous feline civil servants.

For over a century, the United Kingdom’s most quietly powerful residents have padded through the halls of 10 Downing Street, not politicians, but cats.

Officially known as the Chief Mousers to the Cabinet Office, these feline civil servants have served through wars, scandals, and more than a dozen Prime Ministers. They’ve been praised, pampered, occasionally scolded, and often adored.

Here’s a look back at the extraordinary cats who’ve kept Britain’s government rodent-free, and occasionally in good humor, for nearly a hundred years.

Rufus of England aka “Treasury Bill”: 1929–1930

The first recorded cat at No. 10 was Rufus of England, an orange cat nicknamed “Treasury Bill.” He arrived under Prime Minister Ramsay MacDonald in 1929, when the Treasury began officially hiring cats “to kill rats and mice in the Prime Minister’s residence.”

Rufus was paid one shilling a week (not bad for a cat in the Great Depression), but his service was brief. By 1930, he was succeeded by another cat, Peter, destined for fame.

Peter: 1929–1946

Peter was a black cat with a loyal following and beloved by staff and civil servants. But he was perhaps too well loved. Fed scraps from every corner of Downing Street, Peter began ignoring his hunting duties.

So the Treasury intervened, setting a strict ration of one penny a day for food.

Peter went on to serve an astonishing five Prime Ministers, including Winston Churchill, before retiring in 1946 at the age of 17.

Bob the “Munich Mouser”: 1937–1943

Serving alongside Peter, Bob became famous after Neville Chamberlain’s 1938 Munich Agreement. Churchill reportedly nicknamed him the “Munich Mouser,” inspiring a bit of verse from amused staffers:

“Did Neville do right on that airplane trip? Speak and we’ll order some fresh catnip!”

Nelson: 1940–1945

When Churchill took office in 1940, he brought his own cat, a brave black stray named Nelson. He once chased off a large dog, Churchill loved him and called him “the bravest cat I ever knew.”

“Did Neville do right on that airplane trip? Speak and we’ll order some fresh catnip!”

Nelson became a symbol of resilience during the Blitz, calmly sitting beside Churchill through air raids. Foreign leaders even sent gifts of catnip in his honor.

He also had a lighthearted rivalry with Bob, the Munich Mouser.

Peter II: 1946–1947

After the war, Peter II briefly carried on the Chief Mouser duties but was tragically hit by a car in 1947. His service was short, but his legacy paved the way for one of Downing Street’s most famous cats.

Peter III: 1947–1964

Peter III was one of the longest-serving mousers in history and became a household name. He appeared on the Home Secretary’s Christmas card, featured in Women’s Realm magazine, and even found himself in the headlines after a minor “incident” near the Cenotaph before a royal ceremony.

Peter III was adored by staff and the public, the first true celebrity cat of Whitehall.

Peta: 1964–1976

A Manx cat gifted from the Isle of Man, Peta arrived with ceremony and a generous allowance of five shillings a week. She even received fan mail.

But Peta’s work ethic was… debatable. She was described as “loud, lazy, and not house-trained.” She once fought with the Prime Minister’s Siamese cat Nemo, sparking what the tabloids called a “minor diplomatic incident.” Still, the nation loved her.

Wilberforce: 1973–1987

Wilberforce became one of the longest-serving Chief Mousers. He was a black and white cat rescued from an RSPCA shelter and served under four Prime Ministers, including Margaret Thatcher.

Thatcher adored him, once bringing him a can of sardines from Moscow. Officials described him simply as “the best mouser in Britain.”

Humphrey: 1988–1997

Humphrey arrived in 1988, named after Sir Humphrey Appleby from Yes Minister. He cost the Cabinet Office £100 a year and became a tabloid celebrity, even accused (and cleared) in the case of the missing robin chicks.

He also made a duck “disappear” before vanishing himself, later found living happily at the Royal Army Medical College.

When he returned, he “issued” a tongue-in-cheek press release:

“I had a wonderful holiday at the Army Medical College, but it’s nice to be back.”

Humphrey retired in 1997, allegedly at the insistence of Cherie Blair, Tony Blair's wife, though that’s still debated.

Sybil: 2007

After a 10-year gap, Sybil, a Scottish cat belonging to Chancellor Alistair Darling, briefly served in 2007.

She became only the second female Chief Mouser, and her expenses were covered by Chancellor Alistair Darling and his family. Sybil preferred Edinburgh’s quieter life and returned home after a short stay.

Larry: 2011–Present

In February 2011, Larry arrived the day after Valentine’s Day, adopted from Battersea Dogs & Cats Home under David Cameron.

Rumor has it he briefly shared duties with Freya, Chancellor George Osborne’s tabby, until Freya left Downing Street in late 2014.

Larry has since seen six Prime Ministers come and go. He befriended (and feuded with) Palmerston, the tuxedo cat from the Foreign Office, and still patrols like he owns the place, which by now, he certainly does.

The Legacy of the Chief Mousers

From Treasury Bill to Larry, the Chief Mousers have seen Britain through war, recovery, and political upheaval. They’ve outlasted cabinets, outwitted mice, and won the affection of a nation.

Prime Ministers may come and go, but the cats of Downing Street stay, keeping calm, carrying on, and reminding everyone that even in the highest office, there’s always room for a bit of purrsonality.

We love you, Larry!

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