Mikasa (三笠) is a pre-dreadnought battleship built for the Imperial Japanese Navy (IJN) in the late 1890s, and is the only ship of her class.

[a][1] The combat experience of the lightly armoured Matsushima-class cruisers during the First Sino-Japanese War of 1894–1895 convinced the Imperial Japanese Navy of weaknesses in the Jeune Ecole naval philosophy, and Japan embarked on a program to modernize and expand its fleet in preparation for further confrontations.

She carried a maximum of 2,000 long tons (2,000 t) of coal which allowed her to steam for 9,000 nautical miles (17,000 km; 10,000 mi) at a speed of 10 knots (19 km/h; 12 mph).

They were mounted in twin-gun barbettes fore and aft of the superstructure which were additionally protected with armoured hoods, thus resembling true gun turrets.

[14] Mikasa, like all the other Japanese battleships of the time, was fitted with four Barr & Stroud FA3 coincidence rangefinders that had an effective range of 7,300 metres (8,000 yd).

Baroness (later Countess) Hayashi, the wife of the then resident minister to Great Britain (later Ambassador), served as Mikasa's sponsor, launching the hull on a rainy, but otherwise perfect ceremony on 8 November 1900.

[21] The ship participated in the action of 13 April when Tōgō successfully lured out a portion of the Pacific Squadron, including Vice Admiral Stepan Makarov's flagship, the battleship Petropavlovsk.

When Makarov spotted the five battleships of the 1st Division, he turned back for Port Arthur and Petropavlovsk struck a minefield laid by the Japanese the previous night.

Emboldened by his success, Tōgō resumed long-range bombardment missions, which prompted the Russians to lay more minefields which sank two Japanese battleships the following month.

[22] During the Battle of the Yellow Sea on 10 August, Mikasa was at the head of the column of Japanese battleships and was one of the primary targets of the Russian ships.

In turn, she concentrated most of her fire upon the battleships Poltava and Tsesarevich although both ships were only lightly damaged by the Japanese shells which generally failed to penetrate any armour and detonated on impact.

During this time, Mikasa was the focus of the Russian fire as the leading ship in the Japanese column and was hit by 6 twelve-inch and 19 six-inch shells.

Knyaz Suvorov's steering was later repaired, but she blundered between the Japanese and Russian fleets several times later in the battle and Mikasa fired three torpedoes at her to no avail.

[24] While Mikasa suffered 113 personnel casualties, the entire Japanese force combined only lost 117 men killed and 583 wounded to all causes during the battle.

[25] Six days after the Treaty of Portsmouth that ended the war was signed, Mikasa sank at her moorings after a fire and magazine explosion at Sasebo on the night of 11/12 September 1905 that killed 251 crewmen.

[14] In 1912, Mikasa came extremely close to suffering another main magazine detonation, when a suicidal sailor attempted to blow her up at anchor near Kobe.

However, at the request of the Japanese government, each of the signatory countries to the treaty agreed that Mikasa could be preserved as a memorial ship with her hull encased in concrete.

When the Japanese and Americans later restored Mikasa in the 1950s they were able to retrieve some of the removed superstructure for restoration, but the majority of the new Mikasa museum ship's superstructure was actually made up of cannibalized sections from the decommissioned Chilean dreadnought battleship Almirante Latorre and, possibly, the Argentine dreadnought battleship ARA Moreno.

[28] In 1955, American businessman John Rubin, formerly of Barrow, England, wrote a letter to the Japan Times about the state of the ship, which was the catalyst for a new restoration campaign.