Accounting for the enormous and amazing development cosmology has made in the past ten years, the long awaited second edition of this highly appraised textbook has been extensively and thoroughly updated. It tells the story of modern astrophysical cosmology from the perspective of one of its most important and fundamental problems - how did the galaxies come about? The author uses this approach to introduce the whole of what may be called "classical cosmology". Moreover he describes how the study the origin of galaxies and larger-scale structures in the Universe has provided us with unique and direct information about the physics of the very early Universe. The material is presented in an informal pedagogical manner, emphasizing the underlying physical content of the subject, and the book is destined to become a favorite text for students.