During World War II heavy artillery remained as important as it had ever been, being the one weapon that could completely dominate any battlefield, even after the introduction of the tank into warfare on a significant scale. Although the definition of heavy artillery varied from user to user, it could reach far into rear areas to disrupt supply routes and depots, and destroy the strongest fortifications and field works. The towed heavy artillery weapons involved between 1939 and 1945 were many and various, ranging from the antique to the latest state of the art. All are described here, grouped under nationality and with their development and distribution backgrounds. Each weapon is provided with a descriptive text, specifications and is illustrated.