Guadalcanal Campaign - Battle of The Tenaru

Battle of The Tenaru

In response to the Allied landings on Guadalcanal, the Japanese Imperial General Headquarters assigned the Imperial Japanese Army's (IJA) 17th Army, a corps-sized command based at Rabaul and under the command of Lieutenant General Harukichi Hyakutake, the task of retaking Guadalcanal. The army was to be supported by Japanese naval units, including the Combined Fleet under the command of Isoroku Yamamoto, which was headquartered at Truk. The 17th Army, at that time heavily involved in the Japanese campaign in New Guinea, had only a few units available. Of these, the 35th Infantry Brigade under Major General Kiyotake Kawaguchi was at Palau, the 4th (Aoba) Infantry Regiment was in the Philippines and the 28th (Ichiki) Infantry Regiment, under the command of Colonel Kiyonao Ichiki, was on board transport ships near Guam. The different units began to move towards Guadalcanal via Truk and Rabaul immediately, but Ichiki's regiment, being the closest, arrived in the area first. A "First Element" of Ichiki's unit, consisting of about 917 soldiers, landed from destroyers at Taivu Point, east of the Lunga perimeter, after midnight on August 19, then made a 9-mile (14 km) night march west toward the Marine perimeter.

Underestimating the strength of Allied forces on Guadalcanal, Ichiki's unit conducted a nighttime frontal assault on Marine positions at Alligator Creek (often called the "Ilu River" on U.S. Marine maps) on the east side of the Lunga perimeter in the early morning hours of August 21. Ichiki's assault was defeated with heavy Japanese losses in what became known as the Battle of the Tenaru. After daybreak, the Marine units counterattacked Ichiki's surviving troops, killing many more of them. The dead included Ichiki, though it has been claimed that he committed seppuku after realizing the magnitude of his defeat, rather than dying in combat. In total, all but 128 of the original 917 members of the Ichiki Regiment's First Element were killed in the battle. The survivors returned to Taivu Point, notified 17th Army headquarters of their defeat and awaited further reinforcements and orders from Rabaul.