The Geometry of Four-ManifoldsThe last ten years have seen rapid advances in the understanding of differentiable four manifolds, not least of which has been the discovery of new 'exotic' manifolds. These results have had far reaching consequences in geometry, topology, and mathematical physics, and have proven to be a mainspring of current mathematical research. This book provides a lucid and accessible account of the modern study of the geometry of four manifolds. Consequently,