Human development has been a continuing attempt to use new materials in ever more sophisticated ways to enhance the quality of human life. Throughout history, we have made materials with a main component based on the principal property required, with small alloying additions to provide secondary properties.But recently, there has been a revolution as we have discovered how to make much more complex mixtures, providing completely new materials, requiring entirely new scientific theories, and massively extending our ability to make useful products. These new materials are called multicomponent or high-entropy materials. This is the first textbook on the fundamentals of these new multicomponent high-entropy materials. It includes contextual chapters on the history and future potential for developing humankind as driven by the discovery of new materials, and core chapters on methods for discovering and manufacturing multicomponent high-entropy materials, their underlying thermodynamic and