HMS Bellerophon was the lead ship of her class of three dreadnought battleships built for the Royal Navy in the first decade of the 20th century.

Aside from participating in the Battle of Jutland in May 1916 and the inconclusive action of 19 August, her service during the First World War generally consisted of routine patrols and training in the North Sea.

The design of the Bellerophon class was derived from that of the revolutionary[Note 1] battleship HMS Dreadnought, with a slight increase in size, armour and a more powerful secondary armament.

The turbines were rated at 23,000 shaft horsepower (17,000 kW) and intended to give the ship a maximum speed of 21 knots (39 km/h; 24 mph).

During Bellerophon's sea trials on 2 November 1908, she reached a top speed of 21.64 knots (40.08 km/h; 24.90 mph) from 26,836 shp (20,012 kW).

The ship carried enough coal and fuel oil to give her a range of 5,720 nautical miles (10,590 km; 6,580 mi) at a cruising speed of 10 knots (19 km/h; 12 mph).

[3] The Bellerophon-class ships had a waterline belt of Krupp cemented armour that was 10 inches (254 mm) thick between the fore and aftmost barbettes.

In addition, a single three-inch (76 mm) anti-aircraft (AA) gun was added on the former searchlight platform between the aft turrets.

[12] By May 1916, a director had been installed high on the forward tripod mast, but it was not fully wired up by the end of the month when the Battle of Jutland was fought.

She was a participant in combined fleet manoeuvres in June–July and was reviewed by King Edward VII and Tsar Nicholas II of Russia during Cowes Week on 31 July.

The ship took part in fleet manoeuvres in April and July[17] and Evan-Thomas was relieved by Captain Trevylyan Napier on 16 August[13] before she began a refit in late 1910 at Portsmouth.

Bellerophon participated in the combined exercises for the Mediterranean, Home and Atlantic Fleets in January 1911 and she was lightly damaged in a collision with the battlecruiser Inflexible on 26 May.

The ship was en route for her scheduled refit at Gibraltar on 26 July when she was recalled to join the Home Fleet at Scapa Flow.

On the evening of 22 November, the Grand Fleet conducted a fruitless sweep in the southern half of the North Sea; Bellerophon stood with the main body in support of Vice-Admiral David Beatty's 1st Battlecruiser Squadron.

[20] On the evening of 23 January, the bulk of the Grand Fleet sailed in support of Beatty's battlecruisers,[21] but they were too far away to participate in the ensuing Battle of Dogger Bank the following day.

Throughout the rest of the month, the Grand Fleet was performing numerous training exercises before making another sweep into the North Sea on 13–15 October.

On the night of 25 March, Bellerophon and the rest of the fleet sailed from Scapa Flow to support Beatty's battlecruisers and other light forces raiding the German Zeppelin base at Tondern.

On 21 April, the Grand Fleet conducted a demonstration off Horns Reef to distract the Germans while the Imperial Russian Navy relaid its defensive minefields in the Baltic Sea.

About ten minutes later, Bellerophon engaged several German destroyer flotillas with her main armament without result.

[13] The ship was present in Scapa Flow when the battleship Vanguard's magazines exploded on 9 July and her boats rescued two of the three survivors.