The Japanese Navy: From Tsushima to Yamato, and What Sails Under That Flag Today
The Imperial Japanese Navy existed from 1871 to 1945: its greatest victory was the Battle of Tsushima in 1905 under the command of Tōgō Heihachirō. By the start of the Pacific War, the fleet numbered 385 ships, including 10 battleships and the battleship Yamato with 46 cm guns. After 1945 the navy was dissolved; since 1954 its place has been taken by the Maritime Self-Defense Force.
From the first shipyards after the opening of the ports to the Yamato, sunk in 1945, the history of the Japanese navy fits into less than eighty years. We look at how an island closed to the world for three centuries built an ocean-going fleet, which ships from those years can still be seen with your own eyes, and how today's Maritime Self-Defense Force differs by law from the prewar navy.
How an island nation acquired a modern navy
The Imperial Japanese Navy existed from 1871 to 1945. For a country that had been almost entirely closed to foreign relations until the mid-19th century, a modern ocean-going navy was needed quickly: after the opening of the ports, Japan began building shipyards and sending officers to study abroad, taking the British navy as a model. By the early 20th century the country already had its own shipbuilding industry and a trained officer corps.
Tsushima, 1905
On May 27–28, 1905, in the Sea of Japan (Japanese: 日本海海戦), the fleet under the command of Tōgō Heihachirō defeated the Russian squadron that had sailed there across three oceans. The victory led to the Treaty of Portsmouth in September 1905: under its terms Japan received the southern part of Sakhalin and rights to Port Arthur and Dalian.
Ships that remember
| Ship | Years | What it is known for |
|---|---|---|
| Mikasa (三笠) | 1902–1905 in service, since 1926 a museum ship | Flagship at the Battle of Tsushima in 1905; preserved in Yokosuka; called one of the three memorial ships of the world |
| Yamato (大和) | 1941–1945 | A large battleship with 46 cm guns; commissioned on December 16, 1941, sunk on April 7, 1945 |
| Nagato (長門) | 1920–1946 | Flagship of the Combined Fleet longer than any other ship; after the surrender, sunk in July 1946 in nuclear tests at Bikini Atoll |
| Akagi (赤城) | 1927–1942 | One of Japan's first large aircraft carriers; sunk in June 1942 in the Battle of Midway |
The debate over whether such ships were needed
The decision to build super-large battleships like the Yamato was made in 1937, after the London Naval Treaty that limited ship sizes expired. Yamamoto Isoroku and other advocates of aviation objected to the very idea of such ships even at the design stage, considering a focus on aircraft carriers more promising — this is a debate recorded at the time the decision was made, not an assessment in hindsight.
艦 — twenty-one strokes for a warship
艦 — значение: warship, combat ship, vessel — онъёми: カン — 21 штрих(ов). 艦 — 'warship': 21 strokes, one of the most complex characters in the school curriculum. It appears in 軍艦 (ぐんかん), 'warship', and in 艦隊 (かんたい), 'flotilla, squadron'.
How 艦 differs from 船
船 (ふね) — a vessel in general, any kind, from a fishing boat to a ferry; 艦 — specifically a warship. The difference is visible in derived words: 軍艦 — 'warship', 艦隊 — 'flotilla, squadron', 潜水艦 — 'submarine', literally 'diving warship', 艦長 — 'ship's captain'.
| Japanese | Reading | Translation |
|---|---|---|
| 軍艦 | gunkan · gunkan | Warship |
| 艦隊 | kantai · kantai | Flotilla, squadron |
| 潜水艦 | sensuikan · sensuikan | Submarine |
| 艦長 | kanchō · kanchō | Ship's captain |
| 船 | fune · fune | Vessel, ship in general |
Write 艦 along the guides — the character for 'warship' in 軍艦 and 艦隊.
What happened to the navy after 1945
The Imperial Navy was dissolved along with the army under the disarmament policy after the surrender in 1945. By decree of November 30, 1945, the Ministry of the Navy (海軍省) was abolished and transformed into the Second Ministry for Repatriation, which handled the return of sailors home. In June 1946 both departments — the former army and the former navy — were merged into a single repatriation administration.
Why today's ships are called differently
In April 1952, before the San Francisco Treaty came into force, a maritime safety force (海上警備隊) of about 6,000 people was created — for minesweeping and coastal patrol. With the passage of the Self-Defense Forces law in 1954, the force became the Maritime Self-Defense Force (海上自衛隊): by law it defends the country within the framework of Article 9 of the constitution and does not conduct offensive operations, unlike the prewar navy. As of 2019, the authorized strength of the Maritime Self-Defense Force was 45,360 people.
FAQ
- What is the Japanese navy and when was it created?
- The Imperial Japanese Navy was the country's naval force that existed from 1871 to 1945. For an island nation closed to foreign relations for almost three centuries, a modern navy was needed quickly after the opening of the ports: Japan built shipyards and sent officers to study abroad, taking the British navy as a model. After the surrender in 1945 the navy was dissolved.
- What is the Japanese navy famous for?
- The navy's main victory was the Battle of Tsushima on May 27–28, 1905, when the fleet under the command of Tōgō Heihachirō defeated the Russian squadron that had sailed there across three oceans; the victory led to the Treaty of Portsmouth that same year. The navy also built and took through the war the battleship Yamato — with 46 cm guns, commissioned in 1941 and sunk in 1945.
- What happened to the battleship Yamato?
- The Yamato was a battleship with 46 cm guns; the decision to build it was made in 1937, after the London Naval Treaty expired. The ship was commissioned on December 16, 1941, and was sunk on April 7, 1945, during Operation Ten-ichi-gō off Cape Bonomisaki.
- How do you say 'warship' in Japanese?
- 'Warship' in Japanese is 軍艦, read ぐんかん (gunkan): 軍 means 'army', 艦 means 'warship' as opposed to a vessel in general, 船. The same character 艦 appears in 艦隊, 'flotilla', and in 潜水艦, 'submarine', literally 'diving warship'.
- Does the Japanese navy exist today?
- Formally no — the prewar Imperial Navy was dissolved in 1945. Its successor is considered to be the Maritime Self-Defense Force (海上自衛隊): it was created in 1954 on the basis of the maritime safety force that had operated since 1952. As of 2019, the authorized strength of the Maritime Self-Defense Force was 45,360 people.
- How large was the Japanese navy by 1941?
- At the start of the Pacific War, the fleet numbered 385 ships, including 10 battleships, and more than 3,260 aircraft. Among them was the lead ship of the Yamato class with 46 cm guns, commissioned in December 1941.
Sources
Updated: 2026-09-22