Abstract
The oldest Sardinian documents from the twelfth century show that the binomial system of personal identification (first name+surname) was already established. Later sources, however, also reveal that persons could possess more than one surname. This mechanism (sometimes resulting in two, three, or four surnames) permitted men and women to remain identified with both the patriline and the matriline, and worked as well as a kind of kinship mnemonic. This multiplicity of ways of underlining kinship identity (filiation) continued in varying forms until the end of the eighteenth century. Only then did the system of filiation settle into a clearly patrilineal pattern. Yet the older naming customs have not disappeared entirely, and have continued until the present day to lend to the Sardinian onomastic system a kind of “turbulence.”