The Battle of the Coral Sea 4 - 8 May 1942
May 4-8, 1942 - The Battle of the Coral Sea was a major air and naval engagement during World War II, fought between the Americans, Australians and Japanese on May 7-8, 1942.
It marked a major turning point in the Pacific war because it effectively stopped the Japanese advance to the south towards Australia.
The action was precipitated by Japanese attempts to send an invasion force by sea to capture Port Moresby, the major Allied airbase in the region. This would have prevented the Allies using land based air power against Japanese forces in the island regions and allowed Japan to extend its air power over North Queensland.