The Guadalcanal Campaign, also known as the Battle of Guadalcanal and codenamed Operation Watchtower by American forces, was a military campaign fought between 7 August 1942 and 9 February 1943 on and around the island of Guadalcanal in the Pacific theater of World War II. It was the first major offensive by Allied forces against the Empire of Japan.
On August 7th 1942, Allied forces, predominantly United States Marines, landed on Guadalcanal, Tulagi, and Florida in the southern Solomon Islands, with the objective of denying their use by the Japanese to threaten Allied supply and communication routes between the United States, Australia, and New Zealand; powerful American and Australian naval forces supported these landings.
The Allies also intended to use Guadalcanal and Tulagi as bases in supporting a campaign to eventually capture or neutralize the major Japanese base at Rabaul on New Britain. The Japanese defenders, who had occupied those islands since May 1942, were outnumbered and overwhelmed by the Allies, who captured Tulagi and Florida, as well as the airfield – later named Henderson Field – that was under construction on Guadalcanal.