Book excerpt: World War II marked the zenith of railway gun development. Although many of the railway guns deployed at the start of the conflict were of World War I vintage, Germany's ambitious development programme saw the introduction of a number of new classes, including the world's largest, the 80cm-calibre Schwerer Gustav and Schwerer Dora guns, which weighed in at 1,350 tons and fired a huge 7-ton shell. This book provides an overview of the types of railway guns in service during World War II, with a special focus on the German railway artillery used in France, Italy and on the Eastern Front, and analyzes why railway guns largely disappeared from use following the end of the war.