Ahnentafel

An Ahnentafel (or Ahnenreihe) is a genealogical numbering system that allows one to list a person's ancestors in a particular order. It is also known as: the Eytzinger Method, for Michael Eytzinger, the German historian who first published the principles of the system in 1590 [Eytzinger, Michael, "Thesaurus principum hac aetate in Europa viventium, quo progenitores eorum... simul ac fratres et sonores inde ab origine reconduntur... usque ad annum...", Cologne: G. Kempensem, 1590 (1591). Note: In commentaries, his surname may appear in variant forms, including: Aitsingeri, Aitsingero, Aitsingerum, Eyzingern.] ; the Sosa Method, named for Jerónimo (Jérôme) de Sosa, the Spanish genealogist who popularized the numbering system in his work "Noticia de la gran casa de los marqueses de Villafranca" in 1676 [Jouniaux, Léo, "Généalogie : pratique, méthode, recherche", Quercy: Seuil, 2006, pp. 44–45.] ; and the Sosa-Stradonitz Method, for Stephan Kekulé von Stradonitz, the genealogist and son of Friedrich August Kekulé, who published his interpretation of Sosa's method in his "Ahnentafel-atlas" in 1898. [Kekulé von Stradonitz, Stephan, "Ahnentafel-atlas. Ahnentafeln zu 32 Ahnen der Regenten Europas und ihrer Gemahlinnen", Berlin: J. A. Stargardt, 1898-1904. This volume contains 79 charts of the sovereigns of Europe and their wives.]

Ahnentafel is a construct used in genealogy to display a person's ancestry compactly, without the need for a diagram such as a family tree, which is particularly useful in situations where one may be restricted to using plain text, for example in e-mails or newsgroup articles. The term Ahnentafel is a loan word from the German language, however its German equivalent is "Ahnenliste". In German "Ahnentafel" means a genealogical chart showing the ancestors of one person in the form of a binary tree. An Ahnentafel chart may also be called a Kekulé after Stephan Kekulé von Stradonitz.

An Ahnentafel is effectively a method for storing a binary tree in an array by listing the nodes in level-order. The subject of the Ahnentafel is listed as #1, their father as #2 and their mother as #3, then their grandparents as #4 to #7, and so on back through the generations. In this scheme, any person's father has double that person's number, and a person's mother has double the person's number plus one. Apart from #1, who can be male or female, all even-numbered persons are male, and all odd-numbered persons are female. Using this knowledge, you can find out some things without having to compile a list.

How to find the Ahnentafel number, knowing the relation

To find out what someone's number would be without compiling a list, you must first trace how they relate back to the person of interest, meaning you must record that they are their father's mother's mother's father's father's... Once you have done that, you can use two methods.

First method

Use the knowledge that a father's number will be twice the subject's number, or a mother's will be twice plus one, and just multiply and add to 1 accordingly. For instance, we can find out what number Electress Sophia of Hanover would be on an Ahnentafel of Peter Mark Andrew Phillips. Sophia is Peter's mother's mother's father's father's father's mother's father's father's father's father's father's mother. So, we multiply and add.

:1*2+1=3::3*2+1=7:::7*2=14::::14*2=28:::::28*2=56::::::56*2+1=113:::::::113*2=226::::::::226*2=452:::::::::452*2=904::::::::::904*2=1808:::::::::::1808*2=3616::::::::::::3616*2+1=7233

So, if we were to make a list of ancestry for Peter Phillips, Electress Sophia would be #7233.

econd method (binary representation)

This is an elegant and concise way to visualize the genealogical chain between the subject and the ancestor.

: 1. Write down the digit "1", which represents the subject, and, writing from left to right, write "0" for each "father" and "1" for each "mother" in the relation, ending with the ancestor of interest. The result will be the binary representation of the ancestor's Ahnentafel number. Let's try with the Sophia example, translating the chain of relations into a chain of digits. :::Sophia = "Peter's mother's mother's father's father's father's mother's father's father's father's father's father's mother":::Sophia = 1110001000001

: 2. If needed, convert the Ahnentafel number from its binary to its decimal form. A conversion tool might prove handy.

:::Sophia = 1110001000001 (binary):::Sophia = 7233 (decimal)

How to find the relation, knowing the Ahnentafel number

We can also work backwards and find what the relation is from the number.

First method

: 1. You start out by seeing if the number is odd or even. : 2. If it is odd, the last part of the relation is "mother," and you subtract 1 and divide by 2. : 3. If it is even, the last part is "father," and you divide by 2.: 4. Repeat steps 2-3, and build back from the last word.: 5. Once you get to 1, you are done.

So, let's see an example. On an Ahnentafel of HRH Prince William of Wales, Mr John Wark is number 116. We follow the steps:

Example

For a real-life example, here is an ahnentafel of HRH Prince William of Wales, listing all of his ancestors up to his great-great-great-great-grandparents.

# HRH Prince William of Wales (born 21 June 1982)

# HRH The Prince Charles, Prince of Wales (born 14 November 1948)
# Diana Spencer (1 July 1961 – 31 August 1997)

# HRH Prince Philip, Duke of Edinburgh (born 10 June 1921)
# HM Queen Elizabeth II of the United Kingdom (born 21 April 1926)
# Edward Spencer, 8th Earl Spencer (24 January 1924 – 29 March 1992)
# Frances Burke Roche (20 January 1936 – 3 June 2004)

# HRH Prince Andrew of Greece and Denmark (20 January 1882 – 3 December 1944)
# HSH Princess Alice of Battenberg (25 February 1885 – 5 December 1969)
# HM King George VI of the United Kingdom (14 December 1895 – 6 February 1952)
# Elizabeth Bowes-Lyon (4 August 1900 – 30 March 2002)
# Albert Spencer, 7th Earl Spencer (23 May 1892 – 9 June 1975)
# Cynthia Hamilton (16 August 1897 – 4 December 1972)
# Edmund Burke Roche, 4th Baron Fermoy (15 May 1885 – 8 July 1955)
# Ruth Gill (2 October 1908 – 6 July 1993)

# HM King George I of the Hellenes (24 December 1845 – 18 March 1913)
# HIH Grand Duchess Olga Konstantinovna of Russia (3 September 1851 – 18 June 1926)
# HSH Prince Louis of Battenberg, later Louis Mountbatten, 1st Marquess of Milford Haven (24 May 1854 – 11 September 1921)
# HGDH Princess Victoria of Hesse and by Rhine (5 April 1863 – 24 September 1950)
# HM King George V of the United Kingdom (3 June 1865 – 20 January 1936)
# HSH Princess Mary of Teck (26 May 1867 – 24 March 1953)
# Claude Bowes-Lyon, 14th Earl of Strathmore and Kinghorne (14 March 1855 – 7 November 1944)
# Cecilia Cavendish-Bentinck (11 September 1862 – 23 June 1938)
# Charles Robert Spencer, 6th Earl Spencer (30 October 1857 – 26 September 1922)
# The Hon Margaret Baring (14 December 1868 – 4 July 1906)
# James Hamilton, 3rd Duke of Abercorn (30 November 1869 – 12 September 1953)
# Rosalind Bingham (26 February 1869 – 18 January 1958)
# James Burke Roche, 3rd Baron Fermoy (28 July 1852 – 30 October 1920)
# Frances Work (27 October 1857 – 26 January 1947)
# Col William Smith Gill (16 February 1865 – 25 December 1957)
# Ruth Littlejohn (4 December 1879 – 24 August 1964)

# HM King Christian IX of Denmark (8 April 1818 – 29 January 1906)
# HM Queen Luise of Denmark née HSH Princess Luise of Hesse-Kassel (or Hesse-Cassel) (7 September 1817 – 29 September 1898)
# HIH Grand Duke Konstantin Nikolaevitch of Russia (9 September 1827 – 13 January 1892)
# HIH Grand Duchess Aleksandra Iosifovna of Russia née HSH Princess Alexandra of Saxe-Altenburg (8 July 1830 – 23 June 1911)
# HGDH Prince Alexander of Hesse and by Rhine (15 July 1823 – 15 December 1888)
# HSH Princess Julia of Battenberg (12 November 1825 – 19 September 1895)
# HRH Grand Duke Ludwig IV of Hesse and by Rhine (12 September 1837 – 13 March 1892)
# HRH Grand Duchess Alice of Hesse and by Rhine née HRH The Princess Alice of the United Kingdom (25 April 1843 – 14 December 1878)
# HM King Edward VII of the United Kingdom (9 November 1841 – 6 May 1910)
# HM Queen Alexandra of the United Kingdom née HRH Princess Alexandra of Denmark (1 December 1844 – 20 November 1925)
# HH Prince Franz, Duke of Teck (27 August 1837 – 21 January 1900)
# HRH Princess Mary Adelaide, Duchess of Teck née HRH Princess Mary Adelaide of Cambridge (27 November 1833 – 27 October 1897)
# Claude Bowes-Lyon, 13th Earl of Strathmore and Kinghorne (21 July 1824 – 16 February 1904)
# Frances Bowes-Lyon, Countess of Strathmore and Kinghorne née Miss Frances Smith (1830 – 5 February 1922)
# Rev Charles Cavendish-Bentinck (8 November 1817 – 17 August 1865)
# Carolina Burnaby (1833 – 6 July 1918)
# Frederick Spencer, 4th Earl Spencer (14 April 1798 – 27 December 1857)
# Adelaide Spencer, Countess Spencer née Miss Adelaide Seymour (27 January 1825 – 29 October 1877)
# Edward Baring, 1st Baron Revelstoke (13 April 1828 – 17 July 1897)
# Louisa Baring, Baroness Revelstoke née Miss Louisa Bulteel (1839 – 16 October 1892)
# James Hamilton, 2nd Duke of Abercorn (24 August 1838 – 3 January 1913)
# Mary Hamilton, Duchess of Abercorn née Lady Mary Curzon-Howe (23 July 1848 – 10 May 1929)
# George Bingham, 4th Earl of Lucan (8 May 1830 – 5 June 1914)
# Cecilia Bingham, Countess of Lucan née Lady Cecilia Gordon-Lennox (13 April 1835 – 5 October 1910)
# Edmund Burke Roche, 1st Baron Fermoy (August 1815 – 17 September 1874)
# Elizabeth Burke Roche, Baroness Fermoy née Miss Elizabeth Boothby (9 August 1821 – 26 April 1897)
# Frank Work (10 February 1819 – 16 March 1911)
# Ellen Wood (18 July 1831 – 22 February 1877)
# Alexander Ogston Gill
# Barbara Smith Marr (died ca. 30 June 1898)
# David Littlejohn (3 April 1841 – 11 May 1924)
# Jane Crombie (died 19 September 1917)

# HSH Duke Friedrich Wilhelm of Schleswig-Holstein-Sonderburg-Glücksburg (4 January 1785 – 17 February 1831)
# HSH Duchess Luise Karoline of Schleswig-Holstein-Sonderburg-Glücksburg née HSH Princess Luise Karoline of Hesse-Kassel (or Hesse-Cassel) (28 September 1789 – 13 March 1867)
# HSH Landgrave Wilhelm of Hesse-Kassel (or Hesse-Cassel) (24 December 1787 – 5 September 1867)
# HRH Landgravine Charlotte of Hesse-Kassel (or Hesse-Cassel) née HRH Princess Charlotte of Denmark (30 October 1789 – 28 March 1864)
# HIM Emperor Nikolai I Pavlovitch of Russia (25 June 1796 – 18 February 1855)
# HIM Empress Aleksandra Feodorovna of Russia née HRH Princess Charlotte of Prussia (13 July 1798 – 20 October 1860)
# HSH Duke Josef of Saxe-Altenburg (27 August 1789 – 25 January 1868)
# HSH Duchess Amelia of Saxe-Altenburg (28 June 1799 – 28 November 1848)
# HRH Grand Duke Ludwig II of Hesse and by Rhine (26 December 1777 – 16 June 1848)
# HRH Grand Duchess Wilhelmine of Hesse and by Rhine née HGDH Princess Wilhelmine of Baden (10 September 1788 – 27 January 1836)
# Count Moritz von Hauke (26 October 1775 – 29 November 1830)
# Countess Moritz von Hauke née Miss Sophie la Fontaine (1790 – 27 August 1831)
# HGDH Prince Karl of Hesse and by Rhine (23 April 1809 – 20 March 1877)
# HRH Princess Karl of Hesse and by Rhine née HRH Princess Elizabeth of Prussia (18 June 1815 – 21 March 1885)
# HRH Prince Albert of Saxe-Coburg-Gotha, Prince Consort (26 August 1819 – 14 December 1861)
# HM Queen Victoria of the United Kingdom (24 May 1819 – 22 January 1901)
# = 78
# = 79
# = 32
# = 33
# HRH Duke Alexander of Württemberg (9 September 1804 – 4 July 1885)
# Countess Claudine Rhedey von Hohenstein (21 September 1812 – 1 October 1841)
# HRH Prince Adolphus, Duke of Cambridge (24 February 1774 – 8 July 1850
# HRH Princess Adolphus, Duchess of Cambridge née HSH Princess Auguste of Hesse-Kassel (or Hesse-Cassel) (25 July 1797 – 6 April 1889)
# George Bowes-Lyon, Lord Glamis (6 February 1801 – 27 January 1834)
# Charlotte Bowes-Lyon, Lady Glamis née Miss Charlotte Grimstead (1797 – 19 January 1881)
# Oswald Smith (7 July 1794 – 18 June 1863)
# Henrietta Hodgson
# Lord Charles Cavendish-Bentinck (3 October 1780 – 28 April 1826)
# Lady Charles Cavendish-Bentinck née Miss Anne Wellesley (1788 – 19 March 1875)
# Edwyn Burnaby (29 September 1799 – 18 July 1867)
# Anne Salisbury (1805 – 3 May 1881)
# George Spencer, 2nd Earl Spencer (1 September 1758 – 10 November 1834)
# Lavinia Spencer, Countess Spencer née Lady Lavinia Bingham (27 July 1762 – 8 June 1831)
# Sir Horace Seymour (22 November 1791 – 23 November 1851)
# Elizabeth Palk (died 18 January 1827)
# Henry Baring (18 January 1776 – 13 April 1848)
# Cecilia Windham (16 February 1803 – 2 September 1874)
# John Bulteel (died 10 September 1843)
# Elizabeth Grey (10 July 1798 – 8 November 1880)
# James Hamilton, 1st Duke of Abercorn (21 January 1811 – 31 October 1885)
# Louisa Hamilton, Duchess of Abercorn née Lady Louisa Russel (8 July 1812 – 31 March 1905)
# Richard Curzon-Howe, 1st Earl Howe (11 December 1796 – 12 May 1870)
# Anne Curzon-Howe, Countess Howe née Miss Anne Gore (8 March 1817 – 23 July 1877)
# George Bingham, 3rd Earl of Lucan (16 April 1800 – 10 November 1888)
# Anne Bingham, Countess of Lucan née Lady Anne Brudenell (29 June 1809 – 2 April 1877)
# Charles Lennox, 5th Duke of Richmond and Lennox (3 August 1791 – 21 October 1860)
# Caroline Gordon-Lennox, Duchess of Richmond and Lennox née Lady Caroline Paget (6 June 1796 – 12 March 1874)
# Edward Roche (13 July 1771 – 21 March 1855)
# Margaret Curtain (1786 – 21 January 1862)
# James Boothby (10 February 1791 – 28 October 1850)
# Charlotte Cunningham (1799 – 22 January 1893)
# John Wark (1783 – 16 April 1823)
# Sarah Duncan Boude (15 December 1790 – 17 December 1860)
# John Wood (29 July 1785 – 29 January 1848)
# Eleanor Strong (ca. 1803 – 9 July 1863)
# David Gill
# Sarah Ogston
# William Smith Marr (27 November 1810 – 13 February 1898)
# Helen Bean (1814/5 – 20 July 1852)
# William Littlejohn (12 August 1803 – 8 July 1888)
# Janet Bentley (26 January 1811 – 1 October 1848)
# James Crombie (13 January 1810 – 31 January 1878)
# Katharine Forbes (1 December 1812 – 10 April 1893)

Software to create an Ahnentafel

Some genealogy software create an Ahnentafel automatically. See Genealogy software.

Example of computer generated Ahnentafel

Ancestor List ... Self::1. Self, ...: : 1. line of ancestors: :2. father, ...::oo mother:3. mother, ...::oo father: : 2. line of ancestors: :4. father's father, ...::oo father's mother:5. father's mother, ...::oo father's father:6. mother's father, ...::oo mother's mother:7. mother's mother, ...::oo mother's father: 3. line of ancestors: :8. father's father's father, ...::oo father's father's mother:9. father's father's mother, ...::oo father's father's father:10. father's mother's father, ...::oo father's mother's mother:11. father's mother's mother, ...::oo father's mother's father:12. mother's father's father, ...::oo mother's father's mother:13. mother's father's mother, ...::oo mother's father's father:14. mother's mother's father, ...::oo mother's mother's mother:15. mother's mother's mother, ...::oo mother's mother's father

References

ee also

*Cousin chart (Table of consanguinity)
*Family tree
*Genealogical numbering systems
*Genealogy software
*Genogram
*Pedigree chart
*Pedigree collapse