Genealogical Numbering Systems
A multitude of Genealogical Numbering Systems have been developed for indexing family trees and pedigree charts in text format. Each system provides a consistent method to determine the appropriate & predictable identifier for persons in a Family Tree.
Most systems assign identifiers relative to a focal person and are oriented towards Ancestors (an ascending system) or Descendants (a descending system).
The terminology used to refer to this focal person varies, including: subject, proband (from psychiatry & medical genetics; proposito for male proband or proposita for female proband), root node (graphing), progenitor/primogenitor (for descending genealogical numbering systems), de cujus (Latin term meaning 'about which').
- 1 Genealogical Numbering System Support
- 2 Simple numbering
- 3 Ahnentafel Numbering System
- 4 Sosa-Stradonitz
- 5 d'Aboville
- 6 de Villiers
- 7 Henry
- 8 Meurgey de Tupigny
- 9 Modified Register
- 10 Other numbering systems
- 11 Comparative References
- 12 Development Resources
Genealogical Numbering System Support
|Reports||Descendant Systems||Ancestor Systems|
|Charts Fan Chart||Ordering
|Graphical Reports:Descendants Lines||✔|
|Text Reports:Ahnentafel Report||✔|
|Text Reports:Detailed Ancestral Report||✔|
|Text Reports:Descendant Report||✔||✔||✔||✔||✔||✔|
|Text Reports:Detailed Descendant Report||✔||✔||✔|
|Web Pages:Descendant Indented Tree||✔||✔||✔||✔||✔||✔|
Ahnentafel Numbering System
(German for "ancestor table") A tabular layout of genealogical data using an ascending system for numbering pedigree ancestors starting with '1' at a focal person. The number of the father is double that of the child. The mother is double the child's number plus one.
An Austrian nobleman, diplomat, historian, and publicist named Michaël Eytzinger (circa 1530-1598) introduced a new functional theory of numeration of ancestors in 1590 with the Cologne publication of the Thesaurus principum hac aetate in Europa viventium ("lexicon of officials in this age in Europe living"). The Ahnentafel (German for "ancestor table") was first illustrated with a 5 generation pedigree of Henry III of France on pages 146 and 147.
Also called the Kekulé (Kekule) numbering system
Spanish Genealogist Jerónimo de Sosa was a 17th-century Spanish Franciscan friar and a genealogist who based a genealogical numbering system of ancestors on the Ahnentafel numbering system first published by Michaël Eytzinger. Sosa's 1676 work Noticia de la gran casa de los marqueses de Villafranca established a standard.
The system was popularized on a large scale by Stephan Kekulé von Stradonitz (1863–1933) when he published his interpretation of Eytzinger's and Sosa's method in his Ahnentafel-Atlas: Ahnentafeln zu 32 Ahnen der Regenten Europas und ihrer Gemahlinnen, 1898–1904, containing 79 charts of the sovereigns of Europe and their wives. (In 1895, Kekulé's prominent organic chemist father was ennobled by Kaiser Wilhelm II of Germany, giving him the right to add "von Stradonitz" to his name, referring to a possession of his patrilineal ancestors in Stradonice, Bohemia.)
- Sosa-Stradonitz on Wikipedia
Also called the Pama numbering system
A descendant numbering numbering system that assigns letters to generations, and then appends family subgroup birth order numbers. Listed in outline form with a concatenated form used for inline references to the list. In concatenated form, the generations are separated by a decimal point.
Developed in South Africa by Christoffel Coetzee de Villiers 1850-1887 for use in the 1894 posthumous Geslachtregister der Oude Kaapsche Familien. Refined by Dr. Cornelis "Cor" Pama 1916-1994 for the 1966 translation, Genealogies of Old Cape Families.
A descendant numbering system that assigns a birth-order digit for each successive generation since an arbitrary progenitor.
The Henry System is a descending system created by Reginald Buchanan Henry (1881-1969) created a numbering system assigning a number for his 1935 book, Genealogies of the Families of the Presidents. In the original book, each USA President began a new section as was a Progenitor. So they restated the generation count of the list. The President was #1 only if they were a firstborn child. Otherwise, the first digit indexing number was equal to that President's birth order. The progenitor's offspring would be Generation 2 and appended a birth order digit to the index in the 2nd place.
Most notations in the Henry System are a modern reincarnation. In the (outmoded) original Henry System, if there were more than 9 children, the tenth child is given the letter 'X' (in deference to X meaning ten in the Roman Numeral system) and the eleventh child starts alphabetical substitutions with letters A through V. So a 4 digit index of 64B3 would be a child of the fourth generation. That descendant would be described as the 3rd child of the 12th child of the 4th child of the progenitor. And the progenitor was 6th born in their family. The modern Henry System is adapted to computerized sorting and ignores the preconception of the Roman Numeral system. It extends the Hexadecimal numeral system scheme and starts the substitution with 'A' for ten. In the modern Henry system, the 64B3 would have an 11th born child in the 3rd generation spot.
The original book also used an outline form which successively indented for each generation. Although simple to comprehend, the Henry format is not accepted for most genealogical publications.
Modified Henry System
The Modified Henry system assumes a substitution scheme is too confusing. Instead, it uses parenthetical numbers if more than 9 offspring were in a generation. So, the modern Henry system example 64B3 (from the section above) would be represented as 64(11)3 in the Modified Henry system.
Meurgey de Tupigny
A descendant numbering system that assigns Roman numerals to generations, and then appends family subgroup birth order Arabic numbers with a hyphen. Listed in outline form, normally in conjunction with pedigree charts.
Developed in France by Jacques Meurgey de Tupigny 1891-1973 for single surname studies and hereditary nobility line studies. Initially published in the 1956 Guide des recherches généalogiques aux Archives nationales.
Also known as the NGSQ (National Genealogical Society Quarterly) system, "Record System" or the "Modified Register System" Descendant Numbering System
created in 1870 for use in the New England Historical and Genealogical Register (NEHGR) published by the New England Historic Genealogical Society. Adopted with a NGSQs
The big difference between the NGSQ and the Register Systems is that the Record (Modified Register) System only assign a new number for progeny that list descendants later in the index. The NGSQ System assigns a number to every child, whether or not that child is known to have progeny.
- Register-style numbering
- Record System (Modified Register System)
- NGSQ System (Modified Register System) National Genealogical Society Quarterly
Other numbering systems
- Ancestral Lines
- Axtell Genealogy--Numbering System
- Beruck numbering • Christophe Beruck
- Dollarhide System • William "Bill" W. Dollarhide (1942- )
- Forkheim's Numbering System
- GENMTD-L: Numbering System?
- Knot System Sequential
- Yet Another Genealogy Numbering System (ANGUS) • a non-persistent indexing system for computers by Tim Forsythe
- Institute for Genealogical Studies approach • FamilySearch
Articles comparing & contrasting merits of competing numbering sysytems
- Numbering Systems In Genealogy • Richard "Dick" Allen Pence 1932-2009
- Genealogical numbering systems • Wikipedia
- Add a 'numbering' data class - Gramps feature request 0004169
- Show Kekule numbering in different views- Gramps feature request 0007955 (a functional enhancement has been stalled in code review since 2017)
- PseudonymTree.gramps - example (gzip compressed) multi-generational Gramps format Tree that uses intuitive pseudonyms & IDs for testing & exploration use.