The geographical distribution of the principal form of a French surname and
its close variants (in spelling or pronunciation) has been analysed based
on the French births registers, respectively from 1891 to 1915 and from 191
6 to 1940, and on telephone directories for 1975. The spatial analysis of t
he individuals with the principal form of the surname suggests the existenc
e of a positive spatial autocorrelation and three major areas of concentrat
ion in central France, the Loire country and Northern France. Within these
three main areas of concentration, in 1975 most of the telephone subscriber
s with the principal surname are listed in rural communes with fewer than 3
000 inhabitants, suggesting that the geographical pattern is not recent. Mo
reover, between the end of the 19th century and 1975 this pattern remains f
airly constant. The geographical distribution of the holders of a 'variant'
form of the surname shows the existence of a positive correlation between
the absolute frequency of the principal surname and that of the variants, b
ut only one area of concentration appears in Loire country. By analogy with
the theory of centres of origin in genetics and linguistics, it is suggest
ed that this unique area of concentration could be the region in which the
surname originated. If that hypothesis proves to be correct, two main conse
quences follow: large migration movements occurred before the general rural
exodus of the last century, and there has been no major, recent admixture
of populations.