Over the past few years the subject of superstring theory has exploded into a wideranging field covering many areas of modern mathematics, statistical mechanics, elementary particle physics and general relativity. It is appropriate that in this talk I should concentrate on the prospect that superstring theory may provide a unified quantum theory of all the fundamental forces, including gravity. Although it is this prospect that sparked the current interest in the particle physics community the links with mathematics and two-dimensional statistical mechanics have been very fruitful and exciting. This talk will be a very descriptive outline of the principles behind superstring theory and a survey of recent results — the interested reader may refer to any of a large number of references for technical details.*