World War II: Battle of Guadalcanal

US Marine on Guadalcanal
Photograph Courtesy of the US Naval History & Heritage Command

The Battle of Guadalcanal began on August 7, 1942, during World War II (1939-1945).

Armies & Commanders


  • Major General Alexander Vandergrift
  • Major General Alexander Patch
  • up to 60,000 men


  • Lieutenant General Harukichi Hyakutake
  • General Hitoshi Imamura
  • rising to 36,200 men

Operation Watchtower

In the months after the attack on Pearl Harbor, Allied forces suffered a string of reverses as Hong Kong, Singapore, and the Philippines were lost and the Japanese swept through the Pacific. Following the propaganda victory of the Doolittle Raid, the Allies succeeded in checking the advance of the Japanese at the Battle of the Coral Sea. The following month they won a decisive victory at the Battle of Midway which saw four Japanese carriers sunk in exchange for USS Yorktown (CV-5). Capitalizing on this triumph, the Allies began to move to the offensive in the summer of 1942. Conceived by Admiral Ernest King, Commander-in-Chief, US Fleet, Operation Watchtower called for Allied troops to land in the Solomon Islands at Tulagi, Gavutu–Tanambogo, and Guadalcanal. Such an operation would protect the Allied lines of communication to Australia and allow for the capture of a Japanese airfield then under construction at Lunga Point, Guadalcanal.

To oversee the operation, the South Pacific Area was created with Vice Admiral Robert Ghormley in command and reporting to Admiral Chester Nimitz at Pearl Harbor. The ground forces for the invasion would be under the leadership of Major General Alexander A. Vandegrift, with his 1st Marine Division forming the bulk of the 16,000 troops involved. In preparation for the operation, Vandegrift's men were shifted from the United States to New Zealand and forward bases were established or reinforced in the New Hebrides and New Caledonia. Assembling near Fiji on July 26, the Watchtower force consisted of 75 ships led by Vice Admiral Frank J. Fletcher with Rear Admiral Richmond K. Turner overseeing the amphibious forces.

Going Ashore

Approaching the area in poor weather, the Allied fleet remained undetected by the Japanese. On August 7, the landings began with 3,000 Marines assaulting the seaplane bases at Tulagi and Gavutu-Tanambogo. Centered on Lieutenant Colonel Merritt A. Edson's 1st Marine Raider Battalion and the 2nd Battalion, 5th Marines, the Tulagi force was compelled to disembark approximately 100 yards from the beach due to submerged coral reefs. Wading ashore against no resistance, the Marines began securing the island and engaged enemy forces led by Captain Shigetoshi Miyazaki. Though Japanese resistance was fierce on both Tulagi and Gavutu-Tanambogo, the islands were secured on August 8 and 9 respectively. The situation on Guadalcanal was different as Vandegrift landed with 11,000 men against minimal opposition. Pushing forward the next day, they advanced to the Lunga River, secured the airfield, and drove off the Japanese construction troops that were in the area. The Japanese retreated west to the Matanikau River.

In their haste to retreat, they left behind large quantities of food and construction equipment. At sea, Fletcher's carrier aircraft incurred losses as they battled Japanese land-based aircraft from Rabaul. These attacks also resulted in the sinking of a transport, USS George F. Elliott, and a destroyer, USS Jarvis. Concerned about aircraft losses and his ships' fuel supplies, he withdrew from the area on the evening of August 8. That evening, Allied naval forces suffered a severe defeat at the nearby Battle of Savo Island. Caught by surprise, Rear Admiral Victor Crutchley's screening force lost four heavy cruisers. Unaware that Fletcher was withdrawing, the Japanese commander, Vice Admiral Gunichi Mikawa, departed the area after the victory fearing air attack once the sun rose His air cover gone, Turner withdrew on August 9 despite the fact that not all of the troops and supplies had been landed.

The Battle Begins

Ashore, Vandegrift's men worked to form a loose perimeter and completed the airfield on August 18. Dubbed Henderson Field in memory of Marine aviator Lofton Henderson who had been killed at Midway, it began receiving aircraft two days later. Critical to the island's defense, the aircraft at Henderson became known as the "Cactus Air Force" (CAF) in reference to Guadalcanal's code name. Short on supplies, the Marines initially possessed about two weeks' worth of food when Turner departed. Their situation was further worsened by the onset of dysentery and a variety of tropical diseases. During this time, the Marines began patrolling against the Japanese in the Matanikau Valley with mixed results. In response to the Allied landings, Lieutenant General Harukichi Hyakutake, commander of the 17th Army at Rabaul, began shifting troops to the island.

The first of these, under Colonel Kiyonao Ichiki, landed at Taivu Point on August 19. Advancing west, they attacked the Marines early on August 21 and were repulsed with heavy losses at the Battle of the Tenaru. The Japanese directed additional reinforcements to the area which resulted in the Battle of the Eastern Solomons. Though the battle was a draw, it forced Rear Admiral Raizo Tanaka's reinforcement convoy to turn back. As the CAF controlled the skies around the island during daylight hours, the Japanese were compelled to deliver supplies and troops to the island using destroyers.

Holding Guadalcanal

Fast enough to reach the island, unload, and escape before dawn, the destroyer supply line was dubbed the "Tokyo Express." Though effective, this method precluded the delivery of heavy equipment and weapons. His troops suffering from tropical diseases and food shortages, Vandegrift was reinforced and re-supplied in late-August and early-September. Having built up sufficient strength, Major General Kiyotake Kawaguchi attacked the Allied position at Lunga Ridge, south of Henderson Field, on September 12. In two nights of brutal fighting, the Marines held, forcing the Japanese to retreat.

On September 18, Vandegrift was further reinforced, though the carrier USS Wasp was sunk covering the convoy. An American thrust against the Matanikau was checked late in the month, but actions in early October inflicted heavy losses on the Japanese and delayed their next offensive against the Lunga perimeter. With the struggle raging, Ghormley was convinced to dispatch US Army troops to aid Vandegrift. This coincided with a large Express run scheduled for October 10/11. On that evening, the two forces collided and Rear Admiral Norman Scott won a victory at the Battle of Cape Esperance.

Not to be deterred, the Japanese sent a large convoy towards the island on October 13. To provide cover, Admiral Isoroku Yamamoto dispatched two battleships to bombard Henderson Field. Arriving after midnight on October 14, they succeeded in destroying 48 of CAF's 90 aircraft. Replacements were quickly flown to the island and CAF began attacks on the convoy that day but to no effect. Reaching Tassafaronga on the island's western shore, the convoy began unloading the next day. Returning, CAF aircraft were more successful, destroying three cargo ships. Despite their efforts, 4,500 Japanese troops landed.

The Battle Grinds On

Reinforced, Hyakutake had around 20,000 men on Guadalcanal. He believed Allied strength to be around 10,000 (it was actually 23,000) and moved forward with another offensive. Moving east, his men assaulted the Lunga Perimeter for three days between October 23-26. Dubbed the Battle of Henderson Field, his attacks were thrown back with massive losses numbering 2,200-3,000 killed against less than 100 Americans. As the fighting was concluding, American naval forces now led by Vice Admiral William "Bull" Halsey (Ghormley was relieved on October 18) engaged the Japanese at the Battle of the Santa Cruz Islands. Though Halsey lost the carrier USS Hornet, his men inflicted severe losses on the Japanese aircrews. The fight marked the last time that either side's carriers would clash in the campaign.

Exploiting the victory at Henderson Field, Vandegrift began an offensive across the Matanikau. Though initially successful, it was halted when Japanese forces were discovered to the east near Koli Point. In a series of battles around Koli in early November, American forces defeated and drove off the Japanese. As this action was underway, two companies of the 2nd Marine Raider Battalion under Lieutenant Colonel Evans Carlson landed at Aola Bay on November 4. The next day, Carlson was ordered to move overland back to Lunga (approx. 40 miles) and engage enemy forces along the way. During the "Long Patrol," his men killed around 500 Japanese. At Matanikau, Tokyo Express runs aided Hyakutake in strengthening his position and turning back American attacks on November 10 and 18.

Victory at Last

As a stalemate ensued on land, the Japanese made efforts to build up strength for an offensive in late November. To aid in this, Yamamoto made available eleven transports for Tanaka to transport 7,000 men to the island. This convoy would be covered by a force including two battleships that would bombard Henderson Field and destroy the CAF. Aware that the Japanese were moving troops to the island, the Allies planned a similar move. On the night of November 12/13, the Allied covering force encountered the Japanese battleships in the opening actions of the Naval Battle of Guadalcanal. Taking off on November 14, CAF and aircraft from USS Enterprise spotted and sunk seven of Tanaka's transports. Though taking heavy losses the first night, American warships turned the tide on the night of November 14/15. Tanaka's remaining four transports beached themselves at Tassafaronga before dawn but were quickly destroyed by Allied aircraft. The failure to reinforce the island led to the abandonment of the November offensive.

On November 26, Lieutenant General Hitoshi Imamura took command of the newly created Eighth Area Army at Rabaul which included Hyakutake's command. Though he initially began planning for attacks at Lunga, the Allied offensive against Buna on New Guinea led to a shift in priorities as it presented a greater threat to Rabaul. As a result, offensive operations on Guadalcanal were suspended. Though the Japanese won a naval victory at Tassafaronga on November 30, the supply situation on the island was becoming desperate. On December 12, the Imperial Japanese Navy recommended that the island be abandoned. The army concurred and on December 31 the Emperor endorsed the decision.

As the Japanese planned their withdraw, changes occurred on Guadalcanal with Vandegrift and the battle-weary 1st Marine Division departing and Major General Alexander Patch's XIV Corps taking over. On December 18, Patch began an offensive against Mount Austen. This stalled on January 4, 1943, due to strong enemy defenses. The attack was renewed on January 10 with troops also striking ridges known as the Seahorse and the Galloping Horse. By January 23, all objectives had been secured. As this fight was concluding, the Japanese had begun their evacuation which was dubbed Operation Ke. Unsure of Japanese intentions, Halsey sent Patch reinforcements which led to the naval Battle of Rennell Island on January 29/30. Concerned about a Japanese offensive, Patch did not aggressively pursue the retreating enemy. By February 7, Operation Ke was complete with 10,652 Japanese soldiers having left the island. Realizing the enemy had departed, Patch declared the island secured on February 9.


During the campaign to take Guadalcanal, the Allied losses numbered around 7,100 men, 29 ships, and 615 aircraft. Japanese casualties were approximately 31,000 killed, 1,000 captured, 38 ships, and 683-880 aircraft. With the victory at Guadalcanal, the strategic initiative passed to the Allies for the remainder of the war. The island was subsequently developed into a major base for supporting future Allied offensives. Having exhausted themselves in the campaign for the island, the Japanese had weakened themselves elsewhere which contributed to the successful conclusion of Allied campaigns on New Guinea. The first sustained Allied campaign in the Pacific, it provided a psychological boost for the troops as well as led to the development of combat and logistical systems that would be used in the Allies' march across the Pacific. With the island secured, operations continued on New Guinea and the Allies began their "island-hopping" campaign towards Japan.

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Your Citation
Hickman, Kennedy. "World War II: Battle of Guadalcanal." ThoughtCo, Aug. 26, 2020, Hickman, Kennedy. (2020, August 26). World War II: Battle of Guadalcanal. Retrieved from Hickman, Kennedy. "World War II: Battle of Guadalcanal." ThoughtCo. (accessed March 26, 2023).