Although muskets delivered devastating projectiles at comparatively long ranges, their slow rate of fire left the soldier very vulnerable while reloading, and early muskets were useless for close-quarter fighting. Consequently, European infantry regiments of the 17th century were composed of both musketeers and pikemen, who protected the musketeers while loading but also formed the shock component for close-quarter combat. The development of the flintlock musket produced a much less cumbersome and faster-firing firearm. When a short knife was stuck into its muzzle, every soldier could be armed with a missile weapon as well as one that could be used for close combat. The only disadvantage was that the musket could not be loaded or fired while the plug bayonet was in place. The socket bayonet solved this problem and the musket/bayonet combination became the universal infantry weapon from c.1700 to c.1870. The advent of shorter rifled firearms saw the attachment of short swords to rifle barrels. Their longer blades still gave the infantryman the ‘reach’ that contemporaries believed he needed to fend off cavalry attacks. The perfection of the small-bore magazine rifle in the 1890s saw the bayonet lose its tactical importance, becoming smaller and more knife-like, a trend that continued in the world wars. When assault rifles predominated from the 1950s onwards, the bayonet became a weapon of last resort. Its potential usefulness continued to be recognized, but its blade was often combined with an item with some additional function, most notably a wire-cutter. Ultimately, for all its fearsome reputation as a visceral, close-quarter fighting weapon, the bayonet's greatest impact was actually as a psychological weapon. Featuring full-colour artwork as well as archive and close-up photographs, this is the absorbing story of the complementary weapon to every soldier’s firearm from the army of Louis XIV to modern-day forces in all global theatres of conflict.