Genealogical numbering systems

The first Ahnentafel, published by Michaël Eytzinger in Thesaurus principum hac aetate in Europa viventium Cologne: 1590, pp. 146-147, in which Eytzinger first illustrates his new functional theory of numeration of ancestors; this schema showing Henry III of France as n° 1, de cujus, with his ancestors in five generations.

Several genealogical numbering systems have been widely adopted for presenting family trees and pedigree charts in text format.