This book gives an account of the modern view of the global circulation of the atmosphere. It brings the observed nature of the circulation together with theories and simple models of the mechanisms which drive it. Early chapters concentrate on the classical view of the global circulation, on the processes which generate atmospheric motions and on the dynamical constraints which modify them. Later chapters develop more recent themes including low frequency variability and the circulations of other planetary atmospheres. The book will be of interest to advanced students and researchers who wish for an introduction to the subject before engaging with the original scientific literature. The book is copiously illustrated, and includes many results of diagnostic and modelling studies. Each chapter includes a set of problems and bibliographical notes.