International audience As as corollary of the break-down of central power, lineage structures fell into place within the Provençal aristocracy by the years 1020-1030. A quantitative study of the Saint-Victor cartulary shows the importance of this phenomenon : during the Xlth century more than half of its acts were drawn upby extended families. The kinds of family behavior that proceeded from lineage were the following : a very high birthrate, a high rate of marriages, the emergence of sub-lineages and of primogeniture. A new role was vested in kinship in religious mentalities.