The Gun is a novel by C.S. Forester about an imaginary series of incidents involving a single eighteen-pounder cannon during the Peninsular War (1807-1814.) The book was first published in 1933 and has as its background the brutal war of liberation of Spanish and Portuguese forces (regular and partisans) and their English allies against the occupying armies of Napoleonic France. The book vividly portrays the violence of combat and the brutality displayed by both sides in the Peninsular War.