Genealogical numbering systems
Encyclopedia
Family tree
A family tree, or pedigree chart, is a chart representing family relationships in a conventional tree structure. The more detailed family trees used in medicine, genealogy, and social work are known as genograms.-Family tree representations:...
s and pedigree chart
Pedigree chart
A pedigree chart is a diagram that shows the occurrence and appearance or phenotypes of a particular gene or organism and its ancestors from one generation to the next, most commonly humans, show dogs, and race horses....
s in text format. Among the most popular numbering systems are: Ahnentafel (Sosa-Stradonitz Method), and the Register, NGSQ, Henry, d'Aboville, Meurgey de Tupigny, and de Villiers/Pama Systems .
Ahnentafel
AhnentafelAhnentafel
An ahnentafel or ahnenreihe is a genealogical numbering system for listing a person's direct ancestors in a fixed sequence of ascent...
, also known as the Eytzinger Method, Sosa Method, and Sosa-Stradonitz Method, allows for the numbering of ancestors beginning with a descendant. This system allows one to derive an ancestor's number without compiling the list and allows one to derive an ancestor's relationship based on their number.
The number of a person's father is the double of their own number, and the number of a person's mother is the double of their own, plus one. For instance, if the number of John Smith is 10, his father is 20, and his mother is 21.
The first 15 numbers, identifying individuals in 4 generations, are as follows:
(First Generation)
1 Subject
(Second Generation)
2 Father
3 Mother
(Third Generation)
4 Father's father
5 Father's mother
6 Mother's father
7 Mother's mother
(Fourth Generation)
8 Father's father's father
9 Father's father's mother
10 Father's mother's father
11 Father's mother's mother
12 Mother's father's father
13 Mother's father's mother
14 Mother's mother's father
15 Mother's mother's mother
atree
atree or Binary Ahnentafel method uses the same numbering of nodes in the binary ancestors tree as Ahnentafel method, but uses binary numbers instead.For a female in the root the correspondence between binary and atree numbering is straightforward, but for male in the root - the first digit is 1
(i.e. M anyway) - to avoid trimming 0s. The advantage of atree system is easier understanding of the genealogical path (as a path from the root) and binary numbering system is natural for the binary tree.
The first 15 numbers in 4 generations in atree system:
M Subject
MM Father
MF Mother
MMM Father's father
MMF Father's mother
MFM Mother's father
MFF Mother's mother
MMMM Father's father's father
MMMF Father's father's mother
MMFM Father's mother's father
MMFF Father's mother's mother
MFMM Mother's father's father
MFMF Mother's father's mother
MFFM Mother's mother's father
MFFF Mother's mother's mother
Explanation of the correspondence between atree IDs and Ahnentafel decimal IDs:
| person | Ahnentafel format | binary format | atree (for women) | atree (for men) |
|---|---|---|---|---|
| Subject | 1 | 1 | F | M |
| Father | 2 | 10 | FM | MM |
| Mother | 3 | 11 | FF | MF |
| Father's father | 4 | 100 | FMM | MMM |
| Father's mother | 5 | 101 | FMF | MMF |
| Mother's father | 6 | 110 | FFM | MFM |
| Mother's mother | 7 | 111 | FFF | MFF |
Surname methods
Genealogical writers sometimes choose to present ancestral lines by carrying back individuals with their spouses or single families generation by generation. The siblings of the individual or individuals studied may or may not be named for each family. This method is most popular in simplified single surname studies, however, allied surnames of major family branches may be carried back as well. In general, numbers are assigned only to the primary individual studied in each generation.Register System
The Register System uses both common numeralsArabic numerals
Arabic numerals or Hindu numerals or Hindu-Arabic numerals or Indo-Arabic numerals are the ten digits . They are descended from the Hindu-Arabic numeral system developed by Indian mathematicians, in which a sequence of digits such as "975" is read as a numeral...
(1, 2, 3, 4) and Roman numerals
Roman numerals
The numeral system of ancient Rome, or Roman numerals, uses combinations of letters from the Latin alphabet to signify values. The numbers 1 to 10 can be expressed in Roman numerals as:...
(i, ii, iii, iv). The system is organized by generation, i.e., generations are grouped separately.
The system was created in 1870 for use in the New England Historic and Genealogical Register published by the New England Historic Genealogical Society
New England Historic Genealogical Society
The New England Historic Genealogical Society is the oldest and largest genealogical society in the United States, founded in 1845. A charitable, nonprofit educational institution, NEHGS is located at 99-101 Newbury Street, in Boston, Massachusetts, in an eight-story archive and research center....
based in Boston, Massachusetts. Register Style, of which the numbering system is part, is one of two major styles used in the U.S. for compiling descending genealogies. (The other being the NGSQ System.)
(–Generation One–)
1 Progenitor
2 i Child
ii Child (no progeny)
iii Child (no progeny)
3 iv Child
(–Generation Two–)
2 Child
i Grandchild (no progeny)
ii Grandchild (no progeny)
3 Child
4 i Grandchild
(–Generation Three–)
4 Grandchild
5 i Great-grandchild
ii Great-grandchild (no progeny)
6 iii Great-grandchild
7 iv Great-grandchild
NGSQ System
The NGSQ System gets its name from the National Genealogical Society Quarterly published by the National Genealogical SocietyNational Genealogical Society
The National Genealogical Society is a genealogical interest group founded in 1903 in Washington, D.C.. Its headquarters are in Arlington, Virginia....
headquartered in Arlington, Virginia, which uses the method in its articles. It is sometimes called the "Record System" or the "Modified Register System" because it derives from the Register System. The most significant difference between the NGSQ and the Register Systems is in the method of numbering for children who are not carried forward into future generations: The NGSQ System assigns a number to every child, whether or not that child is known to have progeny
Offspring
In biology, offspring is the product of reproduction, of a new organism produced by one or more parents.Collective offspring may be known as a brood or progeny in a more general way...
, and the Register System does not. Other differences between the two systems are mostly stylistic.
(–Generation One–)
1 Progenitor
+ 2 i Child
3 ii Child (no progeny)
4 iii Child (no progeny)
+ 5 iv Child
(–Generation Two–)
2 Child
6 i Grandchild (no progeny)
7 ii Grandchild (no progeny)
5 Child
+ 8 i Grandchild
(–Generation Three–)
8 Grandchild
+ 9 i Great-grandchild
10 ii Great-grandchild (no progeny)
+ 11 iii Great-grandchild
+ 12 iv Great-grandchild
Henry System
The Henry System is a descending system created by Reginald Buchanan Henry for a genealogy of the families of the presidents of the United States that he wrote in 1935. It can be organized either by generation or not. The system begins with 1. The oldest child becomes 11, the next child is 12, and so on. The oldest child of 11 is 111, the next 112, and so on. The system allows one to derive an ancestor's relationship based on their number. For example, 621 is the first child of 62, who is the second child of 6, who is the sixth child of 1.In the Henry System, when there are more than nine children, X is used for the 10th child, A is used for the 11th child, B is used for the 12th child, and so on. In the Modified Henry System, when there are more than nine children, numbers greater than nine are placed in parentheses.
Henry Modified Henry
1. Progenitor 1. Progenitor
11. Child 11. Child
111. Grandchild 111. Grandchild
1111. Great-grandchild 1111. Great-grandchild
1112. Great-grandchild 1112. Great-grandchild
112. Grandchild 112. Grandchild
12. Child 12. Child
121. Grandchild 121. Grandchild
1211. Great-grandchild 1211. Great-grandchild
1212. Great-grandchild 1212. Great-grandchild
122. Grandchild 122. Grandchild
1221. Great-grandchild 1221. Great-grandchild
123. Grandchild 123. Grandchild
124. Grandchild 124. Grandchild
125. Grandchild 125. Grandchild
126. Grandchild 126. Grandchild
127. Grandchild 127. Grandchild
128. Grandchild 128. Grandchild
129. Grandchild 129. Grandchild
12X. Grandchild 12(10). Grandchild
d'Aboville System
The d'Aboville System is a descending numbering method developed by Jacques d'Aboville in 1940 that is very similar to the Henry System, widely used in FranceFrance
The French Republic , The French Republic , The French Republic , (commonly known as France , is a unitary semi-presidential republic in Western Europe with several overseas territories and islands located on other continents and in the Indian, Pacific, and Atlantic oceans. Metropolitan France...
. It can be organized either by generation or not. It differs from the Henry System in that periods are used to separate the generations and no changes in numbering are needed for families with more than nine children. For example:
1 Progenitor
1.1 Child
1.1.1 Grandchild
1.1.1.1 Great-grandchild
1.1.1.2 Great-grandchild
1.1.2 Grandchild
1.2 Child
1.2.1 Grandchild
1.2.1.1 Great-grandchild
1.2.1.2 Great-grandchild
1.2.2 Grandchild
1.2.2.1 Great-grandchild
1.2.3 Grandchild
1.2.4 Grandchild
1.2.5 Grandchild
1.2.6 Grandchild
1.2.7 Grandchild
1.2.8 Grandchild
1.2.9 Grandchild
1.2.10 Grandchild
Meurgey de Tupigny System
The Meurgey de Tupigny System is a simple numbering method used for single surname studies and hereditary nobilityNobility
Nobility is a social class which possesses more acknowledged privileges or eminence than members of most other classes in a society, membership therein typically being hereditary. The privileges associated with nobility may constitute substantial advantages over or relative to non-nobles, or may be...
line studies developed by Jacques Meurgey de Tupigny of the National Archives of France
Archives nationales (France)
The Archives nationales preserve the national archives of the French state, apart from the archives of the Ministry of Defence and the Ministry of Foreign Affairs, as these two ministries have their own archive services, the Service historique de la défense and the Archives diplomatiques...
, published in 1953.
Each generation is identified by a Roman numeral (I, II, III, ...), and each child and cousin in the same generation carrying the same surname is identified by an Arabic numeral. The numbering system usually appears on or in conjunction with a pedigree chart. Example:
I Progenitor
II-1 Child
III-1 Grandchild
IV-1 Great-grandchild
IV-2 Great-grandchild
III-2 Grandchild
III-3 Grandchild
III-4 Grandchild
II-2 Child
III-5 Grandchild
IV-3 Great-grandchild
IV-4 Great-grandchild
IV-5 Great-grandchild
III-6 Grandchild
de Villiers/Pama System
The de Villiers/Pama System gives letters to generations, and then numbers children in birth order. For example:a Progenitor
b1 Child
c1 Grandchild
d1 Great-grandchild
d2 Great-grandchild
c2 Grandchild
c3 Grandchild
b2 Child
c1 Grandchild
d1 Great-grandchild
d2 Great-grandchild
d3 Great-grandchild
c2 Grandchild
c3 Grandchild
In this system, b2.c3 is the third child of the second child, and is one of the progenitor's grandchildren.
The de Villiers/Pama system is the standard for genealogical works in South Africa
South Africa
The Republic of South Africa is a country in southern Africa. Located at the southern tip of Africa, it is divided into nine provinces, with of coastline on the Atlantic and Indian oceans...
. It was developed in the 19th century by Christoffel Coetzee de Villiers and used in his three volume Geslachtregister der Oude Kaapsche Familien (Genealogies of Old Cape Families). The system was refined by Dr. Cornelis (Cor) Pama, one of the founding members of the Genealogical Society of South Africa
Genealogical Society of South Africa
The Genealogical Society of South Africa is a family history society in South Africa. Founded on 18 June 1964, the society today consists of 10 regional branches as well as an electronic branch accessible online....
.
See also
- Ancestral File Number
- AhnentafelAhnentafelAn ahnentafel or ahnenreihe is a genealogical numbering system for listing a person's direct ancestors in a fixed sequence of ascent...
- Cousin chartCousin chartIn kinship terminology, a cousin is a relative with whom one shares one or more common ancestors. The term is rarely used when referring to a relative in one's immediate family where there is a more specific term . The term "blood relative" can be used synonymously and establishes the existence of...
(Table of consanguinity) - Family treeFamily treeA family tree, or pedigree chart, is a chart representing family relationships in a conventional tree structure. The more detailed family trees used in medicine, genealogy, and social work are known as genograms.-Family tree representations:...
- Family tree mappingFamily tree mappingFamily tree mapping is the process of geocoding places in family tree files to produce geospatial data suitable for viewing with a virtual globe or 2D mapping program.-Overview:...
- GEDCOMGEDCOMGEDCOM, an acronym for GEnealogical Data COMmunication, is a proprietary and open de facto specification for exchanging genealogical data between different genealogy software...
- GenogramGenogramA genogram is a pictorial display of a person's family relationships and medical history. It goes beyond a traditional family tree by allowing the user to visualize hereditary patterns and psychological factors that punctuate relationships...
- Kinship terminologyKinship terminologyKinship terminology refers to the various systems used in languages to refer to the persons to whom an individual is related through kinship. Different societies classify kinship relations differently and therefore use different systems of kinship terminology - for example some languages...
- Pedigree chartPedigree chartA pedigree chart is a diagram that shows the occurrence and appearance or phenotypes of a particular gene or organism and its ancestors from one generation to the next, most commonly humans, show dogs, and race horses....
- Pedigree collapsePedigree collapseIn genealogy, pedigree collapse describes how reproduction between two individuals who knowingly or unknowingly share an ancestor causes the number of distinct ancestors in the family tree of their offspring to be smaller than it could otherwise be. Robert C...