Guadalcanal campaign

The Guadalcanal campaign, also known as the Battle of Guadalcanal and codenamed Operation Watchtower by the United States, was an Allied offensive against forces of the Empire of Japan in the Solomon Islands during the Pacific Theater of World War II. It was fought between 7 August 1942 and 9 February 1943, and involved major land and naval battles on and surrounding the island of Guadalcanal. It was the first major Allied land offensive against Japan during the war.

In summer 1942, the Allies decided to mount major offensives in New Guinea and the Solomon Islands with the objectives of defending sea lines to Australia and eventually attacking the major Japanese base at Rabaul on New Britain. The Guadalcanal operation was under the command of Robert L. Ghormley, reporting to Chester W. Nimitz, while the Japanese defense consisted of the Combined Fleet under Isoroku Yamamoto and the Seventeenth Army under Harukishi Hyakutake.

On 7 August 1942, Allied forces, predominantly U.S. Marines, landed on Guadalcanal, Tulagi, and Florida Island in the southern Solomon Islands. The Japanese defenders, who had occupied the islands since May 1942, offered little initial resistance, but the capture of Guadalcanal soon turned into a lengthy campaign as both sides added reinforcements. The Allies captured and completed Henderson Field on Guadalcanal and established a defense perimeter. The Japanese made several attempts to retake the airfield, including in mid-September and in late October. The campaign also involved major naval battles, including the Battles of Savo Island, the Eastern Solomons, Cape Esperance, and the Santa Cruz Islands, culminating in a decisive Allied victory at the Naval Battle of Guadalcanal in mid-November. Further engagements took place at the Battle of Tassafaronga and Battle of Rennell Island. In December, the Japanese decided to abandon Guadalcanal to focus on the defense of the other Solomon Islands, and evacuated their last forces by 9 February 1943.

The campaign followed the successful Allied defensive actions at the Battle of the Coral Sea and the Battle of Midway in May and June 1942. Along with the battles at Milne Bay and Buna–Gona on New Guinea, the Guadalcanal campaign marked the Allies' transition from defensive operations to offensive ones, and effectively allowed them to seize the strategic initiative in the Pacific theater from the Japanese. The campaign was followed by other major Allied offensives in the Pacific, most notably: the Solomon Islands campaign, New Guinea campaign, the Gilbert and Marshall Islands campaign, the Mariana and Palau Islands campaign, the Philippines campaign of 1944 to 1945, and the Volcano and Ryukyu Islands campaign prior to the surrender of Japan in August 1945.