三笠は、ロシアとの戦争を意識した六六艦隊計画（戦艦6隻、装甲巡洋艦6隻を稼働保有する計画）でイギリスに発注された、当時世界最大かつ最新鋭の戦艦でした。当初より連合艦隊旗艦となることを想定していたため、敷島 型の他の同型艦より防御力は格段に向上していました。
日本海海戦では連合艦隊旗艦として東郷平八郎長官が座乗し、第一艦隊第一戦隊の先頭に立ち、バルチック艦隊と壮絶な砲撃戦を繰り広げました。この時「丁字戦法」でバルチック艦隊を殲滅したことは、有名なエピソードとして国内外に語られています。
武勲艦として知られる一方で、実は3度も着底するという不運に付きまとわれた艦でもありました。関東大震災で罹災後、修復と保存を望む国民の声を受けて、様々な困難を克服し、記念艦となりました。大東亜戦争後の荒廃を乗り越え、再び復元され今に至っています。

First-class Battleship HIJMS Mikasa
The Mikasa was ordered from Great Britain as part of the 6-6 (six battleships, six armored cruisers) plan to prepare for war with Russia, and was the most modern warship in the world at that time. Since it was planned from the beginning to use her as a flagship, her protection was greatly upgraded compared to the Shikishima and other ships. In the Battle of Tsushima, she was the flagship of the Japanese Combined Fleet with Admiral Togo Heihachiro on board, was the lead ship of the 1st Squadron of the 1st Fleet, and courageously exchanged fire with the Baltic Fleet. It was at this time that Admiral Togo achieved the famous “Crossing the T” maneuver, which resulted in the annihilation of the Baltic Fleet, and which is still renowned today in Japan and overseas. While Mikasa was known as a ship with excellent military service, she had the misfortune to experience sinking or stranding three times.
After the massive destruction and suffering of The Great Kanto Earthquake, people called for her restoration and preservation, and after overcoming various difficulties, the ship was preserved as a memorial. Having survived the destruction of the Greater East Asian War (the Pacific War), she has been restored to her original condition, and is on display to this day.