The Imperial Japanese Navy (IJN) emerged as one of the world's foremost navies during the interwar period. Before that it had won some resounding victories, and after 1919 began constructing the first aircraft carriers built from the keel up. Japan was among the pioneers of naval aviation that built a series of carriers.

The Hosho was the IJN's first carrier constructed specifically for the launching of planes. It could support up to 15 planes. Even though it was small, it still remained a part of the IJN's naval fleets up to the outbreak of the Pacific War.

The Akagi was a larger IJN carrier that was the queen of its flat tops, and flagship of the first fleet. The IJN added it to its fleet in 1927, and this was the carrier at the forefront of Japan's revolutionary carrier force naval doctrine. This was a fleet of carriers that could transport up to 90 planes such as the A6M, D3A and B5N.

After Japan declared war with China during the 1930s, its aircraft carriers provided air support during the conflict. As relations with the West also declined, Japan stepped up construction of new classes of carriers such as the Soryu and Shokaku-class ships. They included the Zuikaku, Hiryu and Soryu, which by 1941 were a part of the formidable Japanese fleets.

As the Western economic blockade froze oil exports to Japan, its military began planning for war the Pacific. Aircraft carriers were paramount to the navy's plans that included a large-scale airstrike at Pearl Harbor. Japan planned to wipe out the U.S. Pacific Fleet stationed at the harbor, and then invade a variety of territories such as the Philippines and Dutch East Indies.

More than 300 IJN aircraft took to the skies over Hawaii in December 1941. During the airstrike, they ravaged the Pearl Harbor battleships in port and other surface fleet ships. They also bombed airfields that surrounded the harbor. Hundreds of U.S. planes were lost, and the airstrike decimated the battleship fleet at the harbor.

Pearl HarborCredit: This is a public domain image from Wiki Commons.

Japan had won a great victory at Pearl Harbor, but as the U.S. carriers remained firmly intact it was not long before they went head-to-head in naval battles during 1942. The first direct aircraft carrier naval battle was the Battle of Coral Sea, during which the IJN sank the USS Lexington. However, as U.S. planes also bombed a couple of Japan's aircraft carriers, the IJN withdrew before taking Port Moresby.

Admiral Yamamoto planned another operation to wipe out the remaining U.S. carriers soon after the Battle of Coral Sea. For that operation, he targeted the occupation of Midway Island where the navy could trap, and wipe out, U.S. carriers in the surrounding seas. The IJN sent a fleet of four carriers to Midway supported by dispersed surface ship escort groups. As Allied code breakers had deciphered Japanese codes pertaining to the operation, they alerted Midway Island; and the U.S. Navy sent a fleet of carriers to intercept the Japanese armada.

During the Battle of Midway that followed, the U.S. Navy sank the crème of the IJN. The battle began well enough for the IJN as its aircraft wiped out Midway's planes, but the early arrival of the U.S. carriers left the Japanese somewhat flabbergasted. A handful of U.S. SBD dive-bombers broke through the clouds and smashed the IJN's fleet with a precise bombing run that set its ships ablaze. As the Hiryu was also later intercepted and finished off, the Japanese ended the battle with four of their carriers, and hundreds of aircraft, at the bottom of the ocean.

The Battle of Midway was the beginning of the end of the Japanese fleet air arm in the Pacific War. Whilst the IJN still retained a couple of carriers for further naval battles during 1942 and 1943, its aircraft became obsolete. That much was evident during the Battle of the Philippine Sea, in 1944, during which the Japan's navy lost hundreds more planes and three more fleet carriers.

After that battle, the few remaining carriers the navy possessed were short of planes. The IJN sent them to Battle of Leyte Gulf as decoys to lure away the Third Fleet. The Third Fleet took the bait and sailed northwards towards Cape Engano, where it wiped out Japanese aircraft carriers such as the Zuikaku.

Japanese aircraft carriers were seemingly history after the Pacific War.[1] However, more recently Japan has built new helicopter destroyers that are similar to aircraft carriers. Among them, the new Izumo-class helicopter destroyer to support up to 14 helicopters. With its flat decks, the helicopter destroyer is comparable to more standard carriers.

Some have suggested that the construction of new 'helicopter destroyers' is Japanese militarization. But their navy still remains small, and the helicopter destroyers could certainly provide invaluable support for peacetime missions. The Izumo is still someway short of the great IJN fleet aircraft carriers that transformed naval warfare.