Iron Duke class battleships

The Iron Duke class battleships saw the return of the 6in gun, last seen on pre-dreadnought battleships. They were built as part of the 1911 Naval Programme, designed the year after Lord Fisher retired as First Sea Lord. He had been opposed to the reintroduction of the 6in gun, seeing it as a dilution of the all-big-gun concept, but by 1911 the 4in guns used on the major of British dreadnoughts no longer had the range to deal with the threat from destroyers.

HMS Emperor of India and HMS Benbow from HMS Agincourt

The Iron Duke ships were longer and heavier than the previous King George V class ships, mostly to compensate for the increased weight of the 6in guns.  They were also the first British battleships to be built with anti-aircraft guns, in this case a pair of 3in guns intended for use against Zeppelins. They were built with tripod masts to carry the large platforms needed to carry director fire equipment.

HMS Iron Duke and HMS Marlborough had been completed by the outbreak of the First World War. The Iron Duke served as the flagship of the fleet, first for Admiral Sir George Callaghan, and then for Admiral Jellicoe, while the Marlborough served with the 1st Battle Squadron throughout the war.

Benbow and Emperor of India came into service in October and November 1914. They joined the 4th Battle Squadron, fighting with the squadron at Jutland. All four ships took part in the battle of Jutland, fighting in the brief battleship actions.

During the battle HMS Marlborough became the only British dreadnought to be torpedoed. She was hit at around 7pm, probably by a torpedo from the badly damaged Wiesbaden. This was after the first clash between the battlefleets, but before the second clash. Despite having a 70ft by 20ft hole blown in her armour amidships, the Marlborough was still able to serve as the flagship of Admiral Burney during the second clash between the battleships, and she maintained a heavy fire until her list to starboard stopped her from hitting the German ships.

HMS Iron Duke from the right
HMS Iron Duke from the right

HMS Benbow and HMS Marlborough
HMS Benbow and HMS Marlborough

During the night action she began to lose speed. By 10pm Admiral Burney’s division was four miles behind the main fleet, and by the early morning of 1 June her internal bulkheads were threatening to give way. She could only make 10kts safely, and so Admiral Burney was forced to swap his flag to the Revenge and send the Marlboroughback to port. She limped back into harbour at 10kts, and needed three months of repairs.

After the war Benbow, Marlborough and Emperor of India were scrapped to satisfy the terms of the Washington naval treaty. The Iron Duke was retained as a training ship, with her belt armour and two gun turrets removed. During the Second World War she served as a depot ship at Scapa Flow and was finally scrapped in 1946.

Displacement (loaded)


Top Speed



7,780 nautical miles at 10kts

Armour - deck


 - belt


 - bulkheads


 - barbettes


 - turret faces



622ft 9in


Ten 13.5in 45 calibre Mk V guns
Twelve 6in 50 calibre Mk VII guns
Two 3in Mk I AA guns
Four 3pdr guns
Three 21in submerged torpedo tubes

Crew complement






Ships in class

HMS Benbow
HMS Emperor of India
HMS Iron Duke
HMS Marlborough

Books on the First World War | Subject Index: First World War

How to cite this article: Rickard, J (8 November 2007), Iron Duke class battleships ,

Help - F.A.Q. - Contact Us - Search - Recent - About Us - Privacy