This text draws on findings from offshore exploration to present a survey of the geological evolution of part of the Earth's crusts: the British Isles and offshore areas. It includes a description of the oldest rocks present in the Scottish Archaean, through the development of the Caledonian and Hercynian orogenic cycles, to the evolution of NW Europe on the margin of the opening Atlantic Ocean. A full synthesis of geological and geophysical evidence leading to plate tectonic models for the orogenies that have affected NW Europe are given. Contributions come from the fields of geochemistry, igneous and metamorphic petrology, palaeobiology, sedimentology and structural geology.