World War II: The Battle of Mount Austen, the Galloping Horse, and the Sea Horse begins during the Guadalcanal Campaign.

The Battle of Mount Austen, the Galloping Horse, and the Sea Horse, part of which is sometimes called the Battle of the Gifu, took place from 15 December 1942 to 23 January 1943 and was primarily an engagement between United States and Imperial Japanese forces in the hills near the Matanikau River area on Guadalcanal during the Guadalcanal Campaign. The U.S. forces were under the overall command of Alexander Patch and the Japanese forces were under the overall command of Harukichi Hyakutake.

In the battle, U.S. soldiers and Marines, assisted by native Solomon Islanders, attacked Imperial Japanese Army (IJA) forces defending well-fortified and entrenched positions on several hills and ridges. The most prominent hills were called Mount Austen, the Galloping Horse, and the Sea Horse by the Americans. The U.S. was attempting to destroy the Japanese forces on Guadalcanal and the Japanese were trying to hold their defensive positions until reinforcements could arrive.

Both sides experienced extreme difficulties in fighting in the thick jungles and tropical environment of the battle area. Many of the American troops were also involved in their first combat operations. The Japanese were mostly cut off from resupply and suffered greatly from malnourishment and lack of medical care. After some difficulty, the U.S. succeeded in taking Mount Austen, in the process reducing a strongly defended position called the Gifu, as well as the Galloping Horse and the Sea Horse. In the meantime, the Japanese decided to abandon Guadalcanal and withdrew to the west coast of the island. From there most of the surviving Japanese troops were successfully evacuated during the first week of February 1943.