The Battle of the Coral Sea, from 4 to 8 May 1942, was a major naval battle between the Imperial Japanese Navy (IJN) and naval and air forces of the United States and Australia. Taking place in the Pacific Theatre of World War II, the battle was the first naval action in which the opposing fleets neither sighted nor fired upon one another, attacking over the horizon from aircraft carriers instead. It was also the first military battle between aircraft carriers.