The great genealogical work the Jamharat al-nasab [A Collection of Genealogies] of Hisham b. Muhammad al-Kalbi (d. c. 204 ah/819 ce) marks the completion of the codification of Arabic genealogies and forms the basis of most later work. This vast compilation has no parallel in other cultures. The aristocratic families of Western Europe certainly produced elaborate genealogies, sometimes tracing their ancestry back to the Trojans or other figures of classical antiquity. Such genealogies often included collateral branches as well and were not simply the direct stem of the leading branch. The Arabic genealogies, as recorded by Ibn al-Kalbi, remain, however, in a class of their own. In part this is because of the sheer size of the material. The Register of the Jamharat al-nasab contains some 35,000 names, all of people, real and imaginary, most of whom died before the end of the first century hijri [7th ce]. No other genealogies can produce an onomasticon on this scale.

The second distinguishing feature is that this compilation attempts to provide the paternal lineages of an entire nation.…[T]he aim seems to have been to provide as complete account as possible of at least the most important lineages of all the Arab tribes. Written genealogies from other cultures tend to concentrate on the distinguished ancestry of one family or group rather than attempting to portray the structure of a whole nation. Both in size and scope, the written genealogies of Ibn al-Kalbi are unique.