This book gives a comprehensive account of the current understanding of globular clusters and globular cluster systems. We describe the observed properties of these objects and discuss the theoretical ideas that are believed to account for their properties. A key theme of the book is to link the study of globular cluster systems to other areas of astrophysics, such as galaxy formation and evolution. The text is designed for graduate students working in globular cluster research, and as a resource for research astronomers active in this area. We also hope that the connections we emphasize between globular cluster systems and other astrophysical systems will make the book useful to researchers in related fields.

Many people have been instrumental in bringing this book about. The original suggestion that we embark on the project came from Simon Mitton, who accurately described the potential pitfalls and rewards of writing a book. Our editor, Adam Black, has patiently provided advice and encouragement. We are grateful to our copy–editor, Sheila Shepherd, for her careful reading of the original manuscript and her extremely helpful suggestions and corrections, and many others at Cambridge University Press who assisted in bringing this book to fruition. Our own work in the field would not have been possible without our collaborators: Christina Bird, Terry Bridges, David Carter, Alberto Conti, Jayanne English, Kenneth Freeman, Doug Geisler, David Hanes, Ray Sharpies and Joseph Silk. Many other colleagues have provided considerable help in preparing the book, suggesting revisions to earlier versions and providing us with data and figures.