This book provides a comprehensive overview of the structure and evolution of our Galaxy. It is particularly strong in its depiction of models of star formation and of spiral structure, describing and comparing at lenth various approaches, including the author's own. Both observational data and theoretical concepts are presented, offering the reader a broad perspective on the most important and current topics in galactic astronomy, such as chemical evolution, the history of star formation, collapse of the protogalaxy, starbursts and early galactic winds.