Stability theory began in the early 1960s with the work of Michael Morley and matured in the 70s through Shelah's research in model-theoretic classification theory. Today stability theory both influences and is influenced by number theory, algebraic group theory, Riemann surfaces and representation theory of modules. There is little model theory today that does not involve the methods of stability theory. The aim of this book is to provide the student with a quick route from basic model theory to research in stability theory, to prepare a student for research in any of today's branches of stability theory and to give an introduction to classification theory with an exposition of Morley's Categoricity Theorem.