The present volume is a graduate-level introduction to the physics of solid surfaces. It is designed for students of physics, physical chemistry and materials science who are comfortable with modern condensed matter science at the level of, say, Solid State Physics by Ashcroft & Mermin (1976) or Principles of the Theory of Solids by Ziman (1972). In the latter, Ziman points out that scientific knowledge passes from the laboratory to the classroom by a sequence of literary vehicles: original research papers, review articles, monographs and finally textbooks. I believe this book fits well into none of these categories. It is not a textbook – at least not in the traditional sense. The field of surface physics is simply not mature enough to support such an enterprise; too many results are untidy and too many loose ends remain. On the other hand, it is not a review or monograph either. My purpose is neither to set down an established wisdom nor to establish priority among claimants. Indeed, I steadfastly ignore who did what when – except when it is a matter of historical interest.