The mouse of the title is really Peter Sellers, and what roared was Sellers' uniquely anarchic comic talents: he plays three roles, demonstrating his breathtaking acting range, in this somewhat dated but dead-on political satire. In the main one, he is the leader of a tiny country called Grand Fenwick that declares war on the United States in order to receive post-war aid that would rescue it from bankruptcy. In 1959, with Europe still nursing its wounds from World War II and envying the United States' prosperity, the topic was a winning one for both British and American audiences. Based on a novel by Leonard Wibberley, the archly preposterous script supposes that 20 soldiers invade New York clad in chain-mail armor. Sellers is the leader of the invading force as well as the prime minister, but his most hilarious turn involves cross-dressing as the grand duchess. The Mouse That Roared is indispensible for Sellers fans.