The purpose of this book is to present a self-contained and coordinated de­ scription of several design methods for nonlinear control systems, with special emphasis on the problem of achieving stability, globally or on arbitrarily large domains, in the presence of model uncertainties. The book is intended to be a continuation of my earlier book Nonlinear Control Systems, dealing with the fundamentals of the theory of nonlinear control systems, whose third edition was published in 1995. In this respect, it is written in the form of a "second volume" of a single work, and uses a numbering system that continues the one adopted in the earlier book, with which the overlap is essentially insignificant. The book is intended as a graduate text as well as a reference to scientists and engineers interested in the design of feedback laws for nonlinear control systems. In the last decade, methods for global stabilization of nonlinear systems have experienced a vigorous growth.