Phylogeographical studies are available for a considerable number of European species, but few analyses exist for temperate species with very large and fairly continuous populations that are also absent from Northern Europe. Therefore, we studied the butterfly Maniola jurtina as a model for this group. The species has two major genetic lineages (mean genetic distance between lineages: 0.033; FCT: 0.052), most probably evolving in glacial differentiation centres in the western and eastern Mediterranean. The onset of this differentiation might have been the beginning of the last glacial stage maximum some 40 kyr bp. A hybrid zone between these two lineages exists in western Central Europe. No genetic substructures have been found within the two lineages (FSC: 0.017) and average genetic distances are very small. Therefore, it is highly probable that postglacial expansion was of the phalanx type. There is, at most, very limited differentiation at regional and local scales. However, the genetic diversity within populations is high (means: A: 2.68; HE: 17.2%; P: 78%), as would be predicted for such a common species. Comparison of these results with a published allozyme analysis revealed a similar phylogeographical pattern, but lower genetic diversity in the latter. Morphological patterns of wings and genitalia show similar geographical patterns as allozyme data. © 2005 The Linnean Society of London, Biological Journal of the Linnean Society, 2005, 85, 419–431.