The British Population retains a strong sense of regional identity, epitomized by periodic campaigns for Scottish and Welsh devolution, or for Cornish self-government. There have been few studies into the regionalization of British surnames and none that utilize any register that can claim to be nationally representative. The National Social Map presented in this paper is the first comprehensive attempt to create a regional geography of Great Britain based upon the clustering of surnames. The resulting map illustrates a strong relationship between the populations surnames and geographic location. The homogeneity within each of the surname regions identified is striking given that spatial contiguity constraints were not included within the clustering process. The map will hopefully set a bench-mark for future work by geographers in the field of surname research.