who fought in it?
Imperial Japanese Navy vs. Allied naval forces
Battle of Savo Island
was a naval battle of the Pacific Campaign of World War II between the Imperial Japanese Navy and Allied naval forces. 
when did the battle of savo island take place? August 8–9, 1942
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Battle of Savo Island [SEP] Introduction
The Battle of Savo Island, also known as the First Battle of Savo Island and, in Japanese sources, as the , and colloquially among Allied Guadalcanal veterans as The Battle of the Five Sitting Ducks, was a naval battle of the Pacific Campaign of World War II between the Imperial Japanese Navy and Allied naval forces. The battle took place on August 8–9, 1942, and was the first major naval engagement of the Guadalcanal campaign, and the first of several naval battles in the straits later named Ironbottom Sound, near the island of Guadalcanal. The Imperial Japanese Navy, in response to Allied amphibious landings in the eastern Solomon Islands, mobilized a task force of seven cruisers and one destroyer under the command of Vice Admiral Gunichi Mikawa.