I made it with Cartopy , Shapely , and Natural Earth data . The surnames are taken mainly from the appropriate Wikipedia page . Redditors provided data for Sweden , Norway , Lithuania , Latvia , Bulgaria , Macedonia , Serbia , Montenegro , Bosnia and Herzegovina , Turkey , and Catalonia (Ferrer = Smith), as well as corrected my mistakes in Ukraine and Austria . I sincerely appreciate their help. Click on the links to see relevant comments. This is a quick hack, not serious research. The map takes into account countries rather than ethnic or cultural areas (update as of October 1, 2015: now the maps of Spain and Serbia include the most frequent Catalan and Kosovar occupational surnames, respectively). The methodology is simplistic: I always picked the most frequent occupational surname even though Wikipedia aptly notices that in the Netherlands the set of {Smit, Smits, Smid, de Smit, Smet, Smith} outnumbers both {Visser, Visscher, Vissers, de Visser} and {Bakker, Bekke...