Among the oldest of Britain's battleships at the time, Magnificent was a guard ship on the Humber when the First World War broke out.

Her propulsion system consisted of two 3-cylinder triple-expansion steam engines powered by eight coal-fired, cylindrical fire-tube Scotch marine boilers.

[2] The ship was armed with a main battery of four BL 12-inch (305 mm) Mk VIII guns in twin-gun turrets, one forward and one aft.

This allowed Magnificent and her sisters to have a deeper and lighter belt than previous battleships without any loss of protection.

[1] The barbettes for the main battery were protected with 14 in (356 mm) of armor, and the conning tower had the same thickness of steel on the sides.

She was commissioned into the Royal Navy another year later, in December 1895, to relieve the battleship Empress of India as second flagship of the Channel Fleet.

[3] Captain John Ferris was appointed in command in January 1899, and from February the following year she joined the Eastern division of the Channel Fleet,[4] flying the flag of Rear-Admiral Arthur Dalrymple Fanshawe.

On receiving word of the death of Queen Victoria on 21 January 1901 while stationed in Portsmouth, Magnificent flew the Royal Standard at half mast.

[6] He relinquished the position one year later, and at sunset on 5 June 1902 struck his flag on board the Magnificent.

[10] Captain Sackville Carden was appointed in command on 16 October 1902,[11] and took her to visit Gibraltar and Tetuan the following week.

During this service, she was temporarily the flagship of the Commander-in-Chief in November 1907 and underwent a refit at Chatham in 1908 during which she had new fire control systems installed and was converted to burn fuel oil.

[14][15] During a precautionary mobilisation of the fleet immediately prior to the outbreak of First World War, Magnificent and her sister ships Hannibal, Mars, and Victorious on 27 July 1914 formed the 9th Battle Squadron, subordinate to the Admiral of Patrols and stationed at the Humber.

[16] On 9 September 1915, Magnificent was recommissioned to serve along with her similarly disarmed sister ships Hannibal and Mars as a troopship for the Dardanelles campaign.

She departed the Dardanelles in February 1916 after the conclusion of the campaign and returned to England, where she was paid off at Devonport on 3 March 1916.

Magnificent was placed on the disposal list on 4 February 1920, but continued to serve as an ammunition store ship at Rosyth until April 1921.