US Army Memorial on Last Stand Hill,Little Bighorn Battlefield,Montana,USA 11th September 2011

The Battle of the Little Bighorn, known to the Lakota and other Plains Indians as the Battle of the Greasy Grass and commonly referred to as Custer's Last Stand, was an armed engagement between combined forces of the Lakota, Northern Cheyenne, and Arapaho tribes and the 7th Cavalry Regiment of the United States Army. The battle, which occurred June 25–26, 1876, near the Little Bighorn River in eastern Montana Territory, was the most prominent action of the Great Sioux War of 1876.

The fight was an overwhelming victory for the Lakota, Northern Cheyenne, and Arapaho, led by several major war leaders, including Crazy Horse and Chief Gall, inspired by the visions of Sitting Bull (Tȟatȟáŋka Íyotake). The U.S. 7th Cavalry, including the Custer Battalion, a force of 700 men led by George Armstrong Custer, suffered a major defeat. Five of the 7th Cavalry's twelve companies were annihilated; Custer was killed, as were two of his brothers, a nephew, and a brother-in-law. The total U.S. casualty count included 268 dead and 55 severely wounded (six died from their injuries later),including four Crow Indian scouts and two Pawnee Indian scouts.

Public response to the Great Sioux War varied in the immediate aftermath of the battle, but over the next years and decades Custer and his troops became iconic, heroic figures in American history, a status that lasted into the 1960s. The battle, and Custer's actions in particular, have been studied extensively by historians.