Abstract Very little is known about the existence of family names in Ottoman Egypt, except among the upper classes and urban society as a whole. In this respect, the Western Desert Oases of Dakhla and Kharga provide us with an exceptional documentation. Cross referencing texts found or still preserved in local family archives with the results of ethnographical fieldwork conducted over a century, enables us to reconstruct the onomastic culture of the Oases society through the last four centuries. Family names were in use among most of the inhabitants. This use developed in a complex way, by combining lineage names created a few generations ago with more ancient and inclusive names. Their combined use allowed to identify and classify all the inhabitants of a settlement, without knowing them personally. It reflects a non-tribal society, largely based on the ownership of scarce but perennial water resources, a key factor in the longevity of families.