A superbly illustrated history of the Royal Navy's World War II monitors – gunboats armed with a single, large-calibre gun turret – and their roles and battles around the world. When World War II broke out, the Royal Navy possessed a sizeable fleet of battleships and battlecruisers. However, these formed the core of the battle fleets, and were rarely free to perform an equally vital mission – the naval bombardment of targets ashore. In the first book to focus on the subject, naval expert Angus Konstam explains how the monitor, an unusual warship extensively used in World War I, found a new purpose. Although neither fast nor very well-protected, the monitors had a fearsome armament – two 15in guns, the same calibre as many of Britain's battleships. Designed to outrange shore batteries, the monitors could supply flexible, deadly gunfire support to Allied forces ashore. The World War I-era Erebus and Terror were refitted and sent to war, while a new class, the Roberts class, joined them in 1941 and 1943. These warships saw action with the Eastern Fleet and were particularly useful in the Mediterranean, from supporting the campaign in North Africa to providing anti-aircraft defence in besieged Malta and Crete. They then joined the Allied landings from Sicily to Normandy. Illustrated with profiles, battlescenes and a cutaway of Roberts, this book also explains how naval gunfire support was conducted during the war.