nearby small islands as well as the Japanese airfield under construction at Lunga Point on Guadalcanal. The Allies later renamed the airfield Henderson Field. Allied aircraft operating out of Henderson were called the "Cactus Air Force" (CAF) after the Allied code name for Guadalcanal. To protect the airfield, the U.S. Marines established a perimeter defense around Lunga Point. Additional reinforcements over the next two months later increased the number of U.S. troops at Lunga Point on Guadalcanal to more than 20,000. In response to the Allied landings on Guadalcanal, the Japanese Imperial General Headquarters assigned the Imperial Japanese Army's 17th Army—a corps-sized command based at Rabaul and under the command of Lieutenant General Harukichi Hyakutake—with the task of retaking Guadalcanal. Units of the 17th Army began to arrive on Guadalcanal on 19 August to drive Allied forces from the island. Because of the threat by CAF aircraft based at Henderson Field, the Japanese were unable to use large, slow transport ships to deliver troops and supplies to the island. Instead, the Japanese used warships based at Rabaul and the Shortland Islands to carry their forces to Guadalcanal. The Japanese warships—mainly light cruisers or destroyers from the Eighth Fleet under the command of Vice Admiral Gunichi Mikawa—were usually able to make the round trip down "The Slot" to Guadalcanal and back in a single night, thereby minimizing their exposure to CAF air attack. Delivering the troops in this manner, however, prevented most of the soldiers' heavy equipment and supplies, such as heavy artillery, vehicles, and much food and ammunition, from being carried to Guadalcanal with them. These high-speed warship runs to Guadalcanal occurred throughout the campaign and were later called the "Tokyo Express" by the Allies and "Rat Transportation" by the Japanese. Using forces delivered to Guadalcanal in this manner, the Japanese tried three times to retake Henderson Field, but they were defeated each time. First, a reinforced battalion from the 28th Infantry Regiment was defeated in the Battle of the Tenaru on 21 August. Next, the augmented 35th Infantry Brigade was defeated in the Battle of Edson's Ridge on 12–14 September. Finally, the 2nd Infantry Division augmented by one regiment from the 38th Infantry Division was defeated with heavy losses in the Battle for Henderson Field on 23–26 October. Throughout the campaign, the Japanese used Mount Austen (called Bear Height by the Japanese and Mount Mambulu by the local Solomon