Herniation of posterior cranial fossa contents was almost unknown before the publications of the Austrian pathologist Hans Chiari. Although other earlier, scattered, and single descriptions of the various types of hindbrain malformations that he studied had been made, it was Chiari who comprehensively described and categorized these pathological entities. This book presents the first English translation of Chiari's 1896 masterpiece on hindbrain herniations. The importance of these works in the history of medicine cannot be overstated. It is this monumental publication that would go on to pave the way for a better understanding and the development of surgical techniques to treat what has appropriately become known as the Chiari malformations.