The westward drive of the warlike Sioux Indians along a thousand miles of prairie and woodland, from the upper reaches of the Mississippi to the lower Powder River in Montana, is one of the epic migrations of history. From about 1660 to the first quarter of the nineteenth century, the Teton Sioux swept away all opposition: Arikaras, Ponkas, Crees, Crows, Cheyennes--all fell away and dispersed as the Sioux advanced, until the invaders ranged over a vast territory in the northwest, hunting buffalo and raiding their neighbors. During the ensuing years of heavy conflict, between 1865 and 1877, Red Cloud of the Oglalas stood out as one of the greatest of the Sioux leaders. George E. Hyde was born in Omaha, Nebraska, in 1882. As a boy he became interested in Indians and began writing about them in 1910. He has produced some of the most important books on the American Indian ever written, including Indians of the High Plains, Indians of the Woodlands, Red Cloud's Folk, Spotted Tail's Folk, and Life of George Bent, all published by the University of Oklahoma Press. Hyde died in Omaha, Nebraska, in 1968 at the age of 86. Royal B. Hassrick was the author of serveral books on Indians and Indian art, including The Sioux: Customs of a Warrior Society, also published by the University of Oklahoma Press.