The Mouse that Roared is a 1955 novel by Irish writer Leonard Wibberley that launched a series of satirical books about an imaginary country in Europe called the Duchy of Grand Fenwick. Wibberley goes beyond the merely comic, using the situation to make commentary about modern politics and world situations.
Released in February 1955 by Little, Brown, the novel first appeared under the title The Day New York Was Invaded as a Saturday Evening Post serial in six consecutive weeks, from Christmas Day, 1954 through 29 January 1955. The English edition (London: Robert Hale, 1955) bore the author's original title idea, "The Wrath of Grapes", a pun on John Steinbeck's The Grapes of Wrath.
Wibberley published four sequels - Beware of the Mouse (1958), The Mouse on the Moon (1962), The Mouse on Wall Street (1969), and The Mouse that Saved the West (1981) - none of which was as successful.
The phrase "mouse that roared" proved a durable meme over half a century, and is still current. It trades on the title of Edwardian satirist Saki's short story "Filboid Studge, the Story of the Mouse that Helped" , which also features a grand and unexpected success.
Tiny (3 miles by 5 miles) Duchy of Grand Fenwick borders Switzerland and France in the Alps, and proudly retains a pre-industrial economy, dependent almost entirely on making Pinot Grand Fenwick wine. Wibberley places Fenwick in a series of absurd situations, where it goes up against superpowers and wins. In The Mouse that Roared it declares war on the United States after US-produced "Pinot Grand Enwick" wine threatens to undermine their economy.
Expecting to be dealt a crushing defeat (and then rebuild itself through the generous largesse that the United States bestows on its vanquished enemies, as in the Marshall Plan) the tiny Duchy instead defeats the mighty superpower, purely by accident, by capturing the Q-bomb, a prototype doomsday device that could destroy the world if triggered.
The Mouse That Roared was made into a 1959 film starring Peter Sellers in three different roles (as "Duchess Gloriana XII" — as "Count Rupert Mountjoy", the Prime Minister — and as "Tully Bascomb", the military leader), and co-starring Jean Seberg (as "Helen Kokintz", his love interest). Other cast members included: William Hartnell (as Will Buckley), David Kossoff (as Professor Alfred Kokintz), Leo McKern (as "Benter", the Opposition Leader), MacDonald Parke (as "General Snippet"), and Austin Willis (as the "United States Secretary of Defense"). A 1963 sequel was released, based on The Mouse on the Moon.
Some liberties were taken in the film. The lead character of all the books is the Duchess Gloriana XII who is an attractive young royal in the manner of the young Queen Elizabeth II and Princess Grace Kelly of Monaco. In the film Peter Sellers plays the role as a parody of an elderly Queen Victoria with his Mountjoy as a takeoff on Benjamin Disraeli. The Marseilles and New York harbor sequences were filmed in Southampton, UK. The presence of the RMS Queen Elizabeth ocean liner there was a lucky coincidence. In addition, in the book, an encounter with the New York Police Department leads to bloodshed.
Title designer Maurice Binder provided a mouse in a classic opening gag with the Columbia Pictures logo and a return of the mouse in the last scene. In addition to the film's titles, Binder also provided the map in the film.
The Mouse That Roared has also been adapted for the stage by Christopher Seigel, popular in amateur and school theatres.