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The Imperial Japanese Navy (IJN), officially Navy of the Empire of Greater Japan, also known as the Japanese Navy, was the Navy of the Empire of Japan. It was the third largest navy in the world by 1920 behind the United States Navy and the British Royal Navy, and perhaps the most modern at the brink of World War II. It was supported by Imperial Japanese Navy Air Service for aircraft and airstrike operation from the fleet.

Imperial Japanese Navy in Days of Infamy[]

The Imperial Japanese Navy's role in the invasion and conquest of Hawaii in December 1941 was critical. It was only through the efforts of Admiral Isoruku Yamamoto and Commander Minoru Genda of the IJN that the invasion was made possible. Naval pilots, under Mitsuo Fuchida quickly gained superiority of the air and sea by destroying Pearl Harbor and the American ships and planes located there. With the air and sea secure, it was relatively simple matter for the Japanese army to conquer the island of Oahu and break American military resistance.

In June 1942, the Navy, again under the leadership of Yamamoto, beat back an attempted invasion by the United States. Nonetheless, tension between the Imperial Navy and the Army was constant, as each believed itself to be the only arm of the military to be capable of expanding the empire.

The IJN received its first major defeat in 1943 when the United States broke the fleet patrolling Hawaii and shot down most the planes on the islands. Prominent leaders Rear Admiral Tomeo Kaku, Commander Mitsuo Fuchida, and Commander Minoru Genda all died in that invasion.

Imperial Japanese Navy in Joe Steele[]

The Imperial Japanese Navy opened the war in the Pacific for the US when it successfully bombed Pearl Harbor in December 1941.

Imperial Japanese Navy in "News From the Front"[]

After the attack on Pearl Harbor by the Imperial Japanese Navy, many news papers around the country began to question the competency of the Roosevelt administration. As the Japanese scored victory after victory over the US Navy, these questions grew louder and more vocal.

Many reports questioned the wisdom of fighting the Japanese Navy due to their superior equipment, tactics and training. The publishing of military operations allowed the Japanese Navy to intercept Colonel Doolittle's raid on Tokyo before it had a chance to take flight.

Newspapers also leaked evidence that the Japanese Navy's top secret Code had been broken by the US.

The Japanese Navy suffered its first set back at the Battle of the Coral Sea, but the press down played this due to the heavy losses suffered by the US Navy. After this, Japanese submarines sank the Yorktown as it returned to Hawaii for repairs.

The US Navy then launched an operation to take Midway, but due to US papers leaking details of the counter attack, the Japanese Navy soundly defeated the US, and captured Midway.

Imperial Japanese Navy in Southern Victory[]

The 19th & Early 20th Century[]

The Imperial Japanese Navy came into existence in 1869 with accordance of the Meiji restoration to modernize Japan. The IJN scored its first major victory not long afterwards with a victory over the Chinese in the 1st Sino-Japanese War. In the early 20th Century, they defeated the Spanish Navy at battle of Manila in the Hispano-Japanese War. This destroyed the Spanish Pacific fleet, allowing the Japanese to claim the Philippines as part of their empire.

The Great War[]

During the Great War, Japan sided with the Entente, and the Japanese Navy launched a combined effort with the British Pacific Fleet against the US. Their first success occurred when they lured a small US fleet into a submersible ambush, damaging the battleship USS Dakota and sinking the cruiser USS Denver.[1] Next, they sent a squadron up along the Alaskan coast to reinforce the British and Canadian fleet there and helped bottle up the Seattle Squadron.[2] The IJN's major contribution to the war was their combined effort with the RN to destroy the US Pacific Fleet and take back the Sandwich Islands. However, the battle was inconclusive, and both sides withdrew, and the Japanese Navy played a cat and mouse game with their US counterpart until the end of the war.

The Interbellum & the Pacific War[]

After the war's end, the IJN was used to secure the former European colonies of French Indochina, and the Dutch East Indies.

During the 1930s, the IJN shipped gold and arms to Canadian rebels. When the US fleet caught them in the act, an IJN Submarine torpedoed the USS Remembrance, triggering the Pacific War. During this war, the IJN launched it's most successful attack using carriers, by launching an aerial bombardment of Los Angeles, by lopping around the Sandwich Islands supported with oil tankers. Another such aerial attack was launched at the Sandwich Islands themselves, but failed. The war later came to a conclusion with no more major engagements. The war was the first time that carriers had been used.

The Second Great War[]

During the Second Great War, the IJN launched a more successful attack against the US Pacific fleet sinking the USS Remembrance, taking Wake and Midway Islands. Although they had put the US on the defensive in the Pacific, the IJN didn’t press home this advantage, instead the navy went on the defensive itself, leaving only two carriers to counter the US, while its resources went elsewhere.

During the last days of 1942, the US Pacific fleet launched a successful counter attack, sinking the only two carriers in the region. This prompted the IJN to abandon their US holdings, and concentrate against the British Malaya.

Imperial Japanese Navy in The War That Came Early[]

The Imperial Japanese Navy was seen as the only force in Japan that could restrain the Kwantung Army. It frustrated many in the army that the Navy Admirals looked across the Pacific and saw the US as Japan's major threat and not the Soviets.

When war erupted between Japan and the Soviet Union, the Navy played only a minor role, supporting the Army's attack on Vladivostok.

In late 1940, when the United States placed an oil embargo on Japan, the Navy realised they would need the oil rich Dutch East Indies, and the Navy launched offensive operations against the US and European powers in the Pacific in January 1941. The IJN was able to subdue all major fleets in the Asian region but their attack against the US naval base at Pearl Harbor meet with failure. When the US Navy launched it's operation to retake Wake Island, the IJN scored it's biggest victory of the war, sinking all four of the US Navy's remaining fleet carriers, while only losing one of their own, forcing the US to withdraw to Hawaii. With no more opposition, the IJN sent a good chunk of its fleet to assist in the siege of Singapore.

Imperial Japanese Navy in Worldwar[]

The Imperial Japanese Navy had been instrumental in Japan's lighting victories in the Pacific during 1941-2, defeating both the Royal and US Navies.

As the IJN made ready for it's strike on Midway, the Race Invasion caused the US to withdraw, allowing Midway to fall to the Japanese. However, after the Race bombed Tokyo, they abandoned the war and returned to the home islands. During the opening phases of the invasion, their aircraft carriers and battleships raided bases on the Chinese coast, catching many soldiers of the Race off-guard. These actions raised the Race's awareness of the Tosevites' use of boats as weapons. However, Fleetlord Atvar correctly noted that these ships were too large to hide, and the Race was able to track and destroy them if they ever attacked. Throughout the rest of the war, the ships of the IJN played only a minor role in the fight against the Race, as the majority of the fighting was done by its aircraft.


  1. American Front, pgs. 370-374, HC.
  2. Ibid., pg. 469.