Nippon Kaigun
Japanese Navy
Timeline : Superpowers
Naval Ensign of Japan
Commander in Chief Iwakura Isoroku
  • Experditionary Fleet + Pacific Ocean : Yokosuka
  • Main Battleline : Yokosuka
  • Raiding Fleets : Kure
  • Atlantic Ocean + Cuba Defense Force : Guantanamo Bay
  • North Sea : Black Turtle
  • Indian Ocean : Blue Turtle
Headquarters Yokosuka
Ships 30 Supercariers, 220 Carriers, 500 Battleships, 900 Battlecruisers, 1600 Destroyers, over 2100 cruisers & smaller craft, an unknown number of transport ships
Men 5,300,000

The Nippon Kaigun is the naval branch of the Japanese Armed Forces. It is currently the world's largest navy, being larger than that of its two closest rivals combined (The Roman & Mongol Navies). It holds a unique position in the eyes of the Japanese population and it is a symbol of great honor to be accepted into the officer ranks of the navy.

The importance of the Kaigun to the Japanese state can not be overstated, and for most of the nation's history, the navy has been vital in keeping the island nation alive. Japan, as an island, is largely separated from the internal struggles of Asia, but without a powerful navy, the situation could easily fall apart. Not unlike the British Empire was in OTL Europe, the Japanese use their navy to defend their financial interests at sea, allowing them to have an enormous merchant fleet and do business in nearly every corner of the world.

Although the Japanese lack the technology that the Roman Empire has access to it, through its Navy it more than makes up for this in sheer number of ships and crewmen. Furthermore, Japanese naval crews receive better and more extensive training than most Roman crewmen, and globally regarded as the best naval tacticians and navigators. Presently, no other state's navy can best that of Japan.

Operational History


The modern Japanese Navy can trace its roots back to the beginning of Japan's isolation in 1425. Following the end of communication with the outside world, the navy became part of a vital series of defenses that would prevent the Mongols from ever landing on Japan's shore again. Throughout its early history, the navy had relied on thousands of small craft that could be based at one of Japan's two major ports; Yokosuka and Kure. These ships could then be dispatched to deal with any potential invasion by the Mongols, and from 1425-1462, the navy provided Japan with an almost invincible sea wall. With fast-moving ships armed with cannons, these ships presented a threat to any group that tried to land on the shores of Japan.

The only major change in the structure of the navy between 1425 and the end of Japan's isolation was the development of the naval mine in 1462. This changed the navy's role from that of protecting the home islands on their own to one of instead maintaining the naval mine blockade that prevented all ships unaware of the safe passages from entering the waters near the Nipponese homeland.

After Isolation to the Global War

Following the end of Japan's isolation, the Navy went through a period of extreme modernization to bring its technology up to the standards of the Roman Empire, with most noticeably being through the conversion from wind & sail power to electrically powered Ironclads. Armed with cannons and Polybolums, these new ships formed the backbone of the Japanese navy for the next nine years until Japanese & Roman naval strategists realized the potential of all Battleships and Destroyers.

The Japanese and Romans both raced to develop these ships first, but the Romans launched their ships first in 1730 & 1737. The Japanese Navy then went on to recreate their structure so that they could now dominate the seas and control the international trade routes in addition to protecting the home islands. To achieve this goal, the Japanese navy changed the designs of the ships, while the Romans continued to build larger but slower ships, whereas the Japanese chose to build ships that were heavily armed but could reach any ships in the trade routes within an hour. These ships were lightly armored but fast and could outrun any other capital ship in the world (Similar to OTL Battlecruisers).

Between 1737 and the Global War in 1929, the Nippon Kaigun grew from the several thousand small ships that had made up isolationist Japan's Navy to the strongest navy in the world. At the start of the Global War, Japan had 300 Battleships, 500 Battlecruisers, 1400 Destroyers, 800 Light Cruisers, 650 Heavy Cruisers and four Aircraft Carriers.

The Global War

Japanese Battleship Superpowers

Type II Yamato Battleship on patrol in 1885,
Longest serving battleship classes, getting frontline use from 1829 to 1935

The Japanese Navy formed the backbone of the Global Powers naval forces in the Global War. It had its finest hour in 1930, when it held off no less than three invasions by the Mongols. However, it also suffered its worst defeat in the same war as the Incan Navy distracted the Japanese Navy, which allowed the Mongols to land on the Nipponese homeland. However, the Japanese soon bounced back by totally crippling the Mongol navy and developing tactics to deal with the Incan submarines.

Later in the war, the Japanese navy led an assault on the Kor'na Yasse, while the Japanese Navy suffered large losses in the attack; it did convince them of the value of massive airports that could act as a base for aircraft and ships. This would later lead to the creation of the Peninsula-Class Carriers which achieved a similar role in a much smaller package.

Carrier Revolution

The Global War convinced the Japanese Naval Command that they were still the world's best navy, but increasingly, younger members of the establishment urged a change in naval doctrine that would allow them to control the world's shipping without the need for countless numbers of Battlecruisers. Led by the reformist Iwakura Isoroku, these men and women urged a change in doctrine, but they were heavily opposed by the Old Guard. Still, the reformists struck a compromise with the Old Guard, which would revolutionize Japanese naval doctrine. The Current Battlecruiser & Battleship force would be maintained and upgraded, but the High Command authorized the creation of three massive artificial islands (Kame or Turtles) in the major oceans in which Japan did not have a port. These would be supplemented by several hundred raiding flotillas made of cruisers and destroyers, as well as carrier task forces based on the islands that would allow the Nippon Kaigun kōkū-tai (Japanese Naval Air Arm) to project power across the world's oceans.

With the acquisition of Cuba, one of the three Islands was canceled and razed by Japanese forces as it provided them with a stable base in the Atlantic. The final stage of the Carrier Revolution came with the construction of the 30 Peninsula-Class Carriers, which allowed Japan to project power across the world's oceans and allowed the raiding flotillas to refuel and repair without ever having to reach land.


The Japanese Navy is headed by the Kaigun saikō shirei (Naval High Command) which is chosen by the Emperor. The Navy is then divided into five Eriakomando (Area Commands) which are a council made up of Furītoadomiraruzu (Fleet Admirals) and headed by a Eriakomandā (Area Commander) who is chosen by the High Command, The Area Commander then choses the fleet admirals from within each task group. Beneath the Fleet Admirals are the Sentai shirei-kan (Squadron Commanders) which vary in number between seven and eight. Each Squadron Commander heads a squadron made up of one Supercarrier and escorts and they are chosen purely on merit. Below them are Kyaputenzu (Captains) who each command a flotilla of 12. Within the flotillas each ship is commanded by a Fuku sōjū-shi (First Officer) and subservient to him are the Sōda-shu (Helmsman), Hōjutsu shōkō (Gunnery Officer), Furaito yakuin (Flight Officer) and various Shōi (Ensigns). Bellow them are Midshipmen, Petty Officers, Able Seamen and Sailors.

Outside this ranking structure are the commanders of the raiding flotillas that patrol the world's oceans. These are commanded by Raidingu yakuin (Raiding Officers) while the remainder of the flotillas are manned by an all-volunteer force that have the rank of Meiyo sērāzu (Honoured Sailor)

Ranks of the Japanese Navy
Insignia Fleet Admiral Area Commander Squadron Commander proper Captain First Officer Flight officer Gunnery Officer Gunnery Officer Midshipman 100px-Rank insignia of jōtōheisō of the Imperial Japanese Navy.svg 100px-Rank insignia of ittōheisō of the Imperial Japanese Navy.svg 100px-Rank insignia of nitōheisō of the Imperial Japanese Navy.svg
Title Area Commander Fleet Admiral Squadron Commander Captain First Officer Helmsman/Flight Officer Gunnery Officer Ensign Midshipman Petty Officer Able Seamen Sailor

Fleet Structure

The Japanese Navy has the following fleet structure;

  • Flagship (Area Commanders Flagship)
    • Command Squadron (Fleet Admirals Flagship & Escorts)
      • Squadron (Capital Ships & Escorts)
        • Command Flotilla (Squadron Commanders Flagship + Escorts)
          • Flotilla (1 capital ship + Escorts)
            • Individual Ships
  • Raiding Flotilla
    • Individual Ships


The Complement of the Japanese Navy is as follows;

  • Home Fleet; 500 Battleships + Escorts
  • Expeditionary Fleet; 500 Battlecruisers + Escorts
  • Pacific Fleet; Eight Supercarriers, 38 Carriers + Escorts
  • Atlantic Fleet/Cuban Force; eight Supercarriers, 38 Carriers + Escorts
  • North Sea; Seven Supercarriers, 37 Carriers + Escorts
  • Indian Ocean; Seven Supercarriers, 37 Carriers + Escorts
  • Raiding Flotillas; 200 Battlecruisers, 900 Heavy & Light Cruisers + Escorts


As the Japanese navy is the second oldest in the world and is regarded in the best of the world they have a unique set of traditions and ideas. Noticeably the Japanese Navy's sailors are the most disciplined in the world and are incredibly confident in their own abilities, however they are not arrogant and this self-confidence is well founded as the Japanese Navy has only ever lost one battle.

Ships Badges

The Japanese Navy assigns badges to every ship, submarine, squadron and shore establishment. Prior to the age of ironclads, ships were identified by the symbols on their sails. With the removal of the sails, ships badges and mottoes were created to graphically represent the ships. The Naval Crown adorns the top of all the badges. The frame is gold rope. Originally, different classes of ships had different shapes, but currently all ships and submarines have a circular design. Shore establishments have an offset square design.

Fleet reviews

The Fleet Review is an irregular tradition of assembling the fleet before the Emperor. For example, at the most recent Review on February 17 2000 to mark 70 years after the battle of the channel in which the Japanese Home Fleet held the entire Mongul navy at bay, 1356 ships of the JN, and two other nations (the Romans and the Mayans), were present.


Originally subordinates would uncover (remove their headgear) to a superior. But the daughter of Emperor Iyo Hito commented that she disliked seeing the men's heads uncovered and so the Navy adapted a hand salute instead.

The personal salute with the hand is borrowed from the military salute of the Army, and there are various theories concerning its origin. There is the traditional theory that it has been the custom from time immemorial for a junior to uncover to a superior, and even today men on entrance of the officer's academy remove their hats. In this theory, the naval salute is merely the first motion of removing one's head dress.


The Toasts of the Japanese Navy are a set of traditional drinking toasts.

Day Toast
Sunday "Absent Friends"
Monday "Our Ships at Sea"
Tuesday "Our Men"
Wednesday "Ourselves" (As no one else is likely to concern themselves with our welfare!)
Thursday "A Bloody War or a Sickly Season"
Friday "A Willing Foe and Sea-Room"
Saturday "Sweethearts and Wives" (May they never meet!)

The words in brackets are understood but unspoken, though often those not toasting will say them in response. By tradition, these toasts were proposed immediately after the loyal toast, on the relevant day of the week.

While most of these toasts are self-explanatory, "a bloody war or a sickly season" refers to the desire and likelihood of being promoted when many people die: during war or sickness. The Navy traditionally makes the loyal toast seated, due to the evident danger of low deckheads on wooden sailing ships.


Ships will engage in a number of affiliations with cities (e.g., ENS (Emperors Navy Ship) Tokyo with Tokyo), elements of the other forces (e.g., ENS Korea with the Korean Air Regiment), schools, cadet units and charities.

Comparison with OTL

It is almost impossible to compare the Nippon Kaigun to any OTL navy, as no navy in the history of the world has had access to so many ships and is as well trained. However, the current Japanese naval situation is at least somewhat comparable to the post-WWI Royal Navy of the British Empire, as it possessed the same ability to dominate the world's oceans and possesses the same confidence in its own ability.

See Also

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