Foundations of Hyperbolic Manifolds This book is an exposition of the theoretical foundations of hyperbolic manifolds. It is intended to be used both as a textbook and as a reference. The reader is assumed to have a basic knowledge of algebra and topology at the first year graduate level of an American university. The book is divided into three parts. The first part Chapters 1 7 is concerned with hyperbolic geometry and discrete groups. The second part Chapters 8 12 is devoted to the theory of hyperbolic manifolds. The third part Chapter 13 integrates the first two parts in a development of the theory of hyperbolic orbifolds. There are over 500 exercises in this book and more than 180 illustrations