The lecture is an attempt to show the way in which research upon the Quaternary Period in Britain is being affected by the application to it of radiocarbon dating. Mild interstadial periods during the last glaciation can be distinguished, set in sequence and related to similar European interstadials. It is shown that a brief climatic oscillation occurs widely in the Late-glacial transition from Full-glacial to Post-glacial time, and that the vegetational changes registered in pollen zonations of the Post-glacial Period are to some degree synchronous. They reflect widespread climatic changes, as do major horizons in bog stratigraphy that can also be correlated by radiocarbon dating. The method has a most powerful application to archaeology and it promises some resolution of the complex interaction of eustatic, isostatic and tectonic factors that have affected those relative movements of land and sea level recorded by the submerged forests, estuarine formations and raised beaches of the British Isles. Between the results of British Quaternary study in these and other fields there is developing considerable consistency of pattern, as also between British Quaternary History and that of other parts of the world.