The Battle of the Coral Sea, a major engagement of the Pacific Theatre of World War II, was fought 4–8 May 1942 in the waters east of New Guinea and south of the Bismarck Islands between elements of the Imperial Japanese Navy and Allied naval and air forces from the United States (U.S.) and Australia.
To extend their empire in the Pacific to the conquest of Australia, the Japanese first had to capture the naval and air center of Port Moresby on the southeast coast of New Guinea.
In order to extend the reach of their air searches for Allied naval forces, they resolved to simultaneously establish a seaplane base at Tulagi in the lower Solomon Islands.
The U.S. learned of the Japanese plan, known as Operation Mo, through signals intelligence and sent two United States Navy carrier task forces and a joint Australian-American cruiser force to oppose the Japanese offensive.
Task Force MO Vice Admiral Shigeyoshi Inoue, Commander, Fourth Fleet in light cruiser Kashima anchored at Rabaul[1] Vice Admiral Takeo Takagi in heavy cruise Myōkō[2] Rear Admiral Aritomo Gotō in heavy cruiser Aoba Captain Noboru Ishizaki Rear Admiral Frank Jack Fletcher in Yorktown[45] General Douglas MacArthur[52] Port Moresby garrison