Genealogical numbering systems
Several genealogical numbering systems have been widely adopted for presenting family trees and pedigree charts in text format.
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.
A family tree, also called a genealogy or a pedigree chart, is a chart representing family relationships in a conventional tree structure. More detailed family trees, used in medicine and social work, are known as genograms.
Three generations of ancestors (born from 1824 to 1916) placed on a Swedish kurbits tree
An ahnentafel family tree displaying an ancestor chart of Sigmund Christoph, Graf von Zeil und Trauchburg
An ahnentafel family tree, showing three generations of the Kennedy family
Family trees are an age-old phenomenon. This example dates from the sixteenth century.