Based on a course given at Oxford over many years, this book is a short and concise exposition of the central ideas of general relativity. The focus is on the chain of reasoning that leads to the relativistic theory from the analysis of distance and time measurements in the presence of gravity, rather than on the underlying mathematical structure. The geometric ideas - which are central to the understanding of the nature of gravity - are introduced in parallel with the development of the theory, the emphasis being on laying bare how one is led to pseudo-Riemannian geometry through a natural process of reconciliation of special relativity with the equivalence principle. At centre stage are the 'local inertial coordinates' set up by an observer in free fall, in which special relativity is valid over short times and distances. In more practical terms, the book is a sequel to the author's Special Relativity in the same series, with some overlap in the treatment of tensors.