Ahnentafel

An Ahnentafel (or Ahnenreihe), also known as the Sosa-Stradonitz System, is a list of a person's ancestors in a particular order. It 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.

It is effectively a traversal of the family tree.

After listing the person as #1, you list 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.

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, 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 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*2+1=7*2=14*2=28*2=56*2+1=113*2=226*2=552*2=1104*2=2208*2=4416*2+1=8833

So, if we were to make a list of ancestry for Peter Phillips, Electress Sophia would be #8833.

We can also work backwards and find what the relation is from the number. To do this, here are the steps.

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:

116/2=58	58/2=29	29-1=28/2=14	14/2=7	7-1=6/2=3	3-1=2/2=1
father	father	mother	father	mother	mother

We reverse that, and we get that #116, Mr John Wark, is Prince William's mother's mother's father's mother's father's father.

Demonstration

1. self
2. father
3. mother
4. father's father
5. father's mother
6. mother's father
7. mother's mother
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

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-grandparents.

1. HRH Prince William of Wales (born June 21, 1982)
2. HRH The Prince Charles, Prince of Wales (born November 14, 1948)
3. Diana, Princess of Wales née Lady Diana Spencer (July 1, 1961-August 31, 1997)
4. HRH Prince Philip, Duke of Edinburgh (born June 10, 1921)
5. HM Queen Elizabeth II of the United Kingdom (born April 21, 1926)
6. Edward Spencer, 8th Earl Spencer (January 24, 1924-March 29, 1992)
7. The Hon Mrs Shand Kydd née The Hon Frances Burke Roche (January 20, 1936-June 3, 2004)
8. HRH Prince Andrew of Greece and Denmark (January 20, 1882-December 3, 1944)
9. HRH Princess Andrew of Greece and Denmark née HSH Princess Alice of Battenberg (February 25, 1885-December 5, 1969)
10. HM King George VI of the United Kingdom (December 14, 1895-February 6, 1952)
11. HM Queen Elizabeth the Queen Mother née Lady Elizabeth Bowes-Lyon (August 4, 1900-March 30, 2002)
12. Albert Spencer, 7th Earl Spencer (May 23, 1892-June 9, 1975)
13. Cynthia Spencer, Countess Spencer née Lady Cynthia Hamilton (August 16, 1897-December 4, 1972)
14. Edmund Burke Roche, 4th Baron Fermoy (May 15, 1885-July 8, 1955
15. Ruth Burke Roche, Baroness Fermoy née Miss Ruth Gill (October 2, 1908-July 6, 1993
16. HM King George I of the Hellenes (December 24, 1845-March 18, 1913)
17. HM Queen Olga of Greece née HIH Grand Duchess Olga Konstantinovna of Russia (September 3, 1851-June 18, 1926)
18. HSH Prince Louis of Battenberg, later Louis Mountbatten, 1st Marquess of Milford Haven (May 24, 1854-September 11, 1921)
19. HGDH Princess Louis of Battenberg, later Victoria Mountbatten, Marchioness of Milford Haven née HGDH Princess Victoria of Hesse and by Rhine (April 5, 1863-September 24, 1950)
20. HM King George V of the United Kingdom (June 3, 1865-January 20, 1936)
21. HM Queen Mary of the United Kingdom née HSH Princess Mary of Teck (May 26, 1867-March 24, 1953)
22. Claude Bowes-Lyon, 14th Earl of Strathmore and Kinghorne (March 14, 1855-November 7, 1944)
23. Cecilia Bowes-Lyon, Countess of Strathmore and Kinghorne née Cecilia Cavendish-Bentinck (September 11, 1862-June 23, 1938)
24. Charles Spencer, 6th Earl Spencer (October 30, 1857-September 26, 1922)
25. Margaret Spencer, Countess Spencer née The Hon Margaret Baring (December 14, 1868-July 4, 1906)
26. James Hamilton, 3rd Duke of Abercorn (November 30, 1869-September 12, 1953)
27. Rosalind Hamilton, Duchess of Abercorn née Lady Rosalind Bingham (February 26, 1869-January 18, 1958)
28. James Burke Roche, 3rd Baron Fermoy (July 28, 1851-October 30, 1920)
29. Frances, Lady Fermoy née Miss Frances Work (October 27, 1857-January 26, 1947)
30. Col William Smith Gill (February 16, 1865-December 25, 1957)
31. Mrs William Smith Gill née Miss Ruth Littlejohn (December 4, 1879-August 24, 1964)
32. HM King Christian IX of Denmark (April 8, 1818-January 29, 1906)
33. HM Queen Luise of Denmark née HSH Princess Luise of Hesse-Kassel (September 7, 1817-September 29, 1898)
34. HIH Grand Duke Konstantin Nikolaevitch of Russia (September 9, 1827-January 13, 1892)
35. HIH Grand Duchess Aleksandra Iosifovna of Russia née HSH Princess Alexandra of Saxe-Altenburg (July 8, 1830-June 23, 1911)
36. HGDH Prince Alexander of Hesse and by Rhine (July 15, 1823-December 15, 1888)
37. HSH Princess Julia of Battenberg (November 12, 1825-September 19, 1895)
38. HRH Grand Duke Ludwig IV of Hesse and by Rhine (September 12, 1837-March 13, 1892)
39. HRH Grand Duchess Alice of Hesse and by Rhine née HRH The Princess Alice of the United Kingdom (April 25, 1843-December 14, 1878)
40. HM King Edward VII of the United Kingdom (November 9, 1841-May 6, 1910)
41. HM Queen Alexandra of the United Kingdom née HRH Princess Alexandra of Denmark (December 1, 1844-November 20, 1925)
42. HH Prince Franz, Duke of Teck (August 27, 1837-January 21, 1900)
43. HRH Princess Mary Adelaide, Duchess of Teck née HRH Princess Mary Adelaide of Cambridge (November 27, 1833-October 27, 1897)
44. Claude Bowes-Lyon, 13th Earl of Strathmore and Kinghorne (July 21, 1824-February 16, 1904)
45. Frances Bowes-Lyon, Countess of Strathmore and Kinghorne née Miss Frances Smith (1830-February 5, 1922)
46. Rev Charles Cavendish-Bentinck (November 8, 1817-August 17, 1865)
47. Mrs Charles Cavendish-Bentinck née Miss Carolina Burnaby (1833-July 6, 1918)
48. Frederick Spencer, 4th Earl Spencer (April 14, 1798-December 27, 1857)
49. Adelaide Spencer, Countess Spencer née Miss Adelaide Seymour (January 27, 1825-October 29, 1877)
50. Edward Baring, 1st Baron Revelstoke (April 13, 1828-July 17, 1897)
51. Louisa Baring, Baroness Revelstoke née Miss Louisa Bulteel (1839-October 16, 1892)
52. James Hamilton, 2nd Duke of Abercorn (August 24, 1838-January 3, 1913)
53. Mary Hamilton, Duchess of Abercorn née Lady Mary Curzon-Howe (July 23, 1848-May 10, 1929)
54. George Bingham, 4th Earl of Lucan (May 8, 1830-June 5, 1914)
55. Cecilia Bingham, Countess of Lucan née Lady Cecilia Gordon-Lennox (April 13, 1835-October 5, 1910)
56. Edmund Burke Roche, 1st Baron Fermoy (August 1815-September 17, 1874)
57. Elizabeth Burke Roche, Baroness Fermoy née Miss Elizabeth Boothby (August 9, 1821-April 26, 1897)
58. Mr Frank Work (February 10, 1819-March 16, 1911)
59. Mrs Frank Work née Miss Ellen Wood (July 18, 1831-February 22, 1877)
60. Mr Alexander Ogston Gill (Dates unknown)
61. Mrs Alexander Smith Gill née Miss Barbara Smith Marr (died ca. June 30, 1898)
62. Mr David Littlejohn (April 3, 1841-May 11, 1924)
63. Mrs David Littlejohn née Miss Jane Crombie (died September 19, 1917)
64. HSH Duke Friedrich Wilhelm of Schleswig-Holstein-Sonderburg-Glücksburg (January 4, 1785-February 17, 1831)
65. HSH Duchess Luise Karoline of Schleswig-Holstein-Sonderburg-Glücksburg née HSH Princess Luise Karoline of Hesse-Kassel (September 28, 1789-March 13, 1867)
66. HSH Landgrave Wilhelm of Hesse-Kassel (December 24, 1787-September 5, 1867)
67. HRH Landgravine Charlotte of Hesse-Kassel née HRH Princess Charlotte of Denmark (October 30, 1789-March 28, 1864)
68. HIM Emperor Nikolai I Pavlovitch of Russia (June 25, 1796-February 18, 1855)
69. HIM Empress Aleksandra Feodorovna of Russia née HRH Princess Charlotte of Prussia (July 13, 1798-October 20, 1860)
70. HSH Duke Josef of Saxe-Altenburg (August 27, 1789-January 25, 1868)
71. HSH Duchess Amelia of Saxe-Altenburg (June 28, 1799-November 28, 1848)
72. HRH Grand Duke Ludwig II of Hesse and by Rhine (December 26, 1777-June 16, 1848)
73. HRH Grand Duchess Wilhelmine of Hesse and by Rhine née HGDH Princess Wilhelmine of Baden (September 10, 1788-January 27, 1836)
74. Count Moritz von Hauke (October 26, 1775-November 29, 1830)
75. Countess Moritz von Hauke née Miss Sophie la Fontaine (1790-August 27, 1831)
76. HGDH Prince Karl of Hesse and by Rhine (April 23, 1809-March 20, 1877)
77. HRH Princess Karl of Hesse and by Rhine née HRH Princess Elizabeth of Prussia (June 18, 1815-March 21, 1885)
78. HRH Prince Albert of Saxe-Coburg-Gotha, Prince Consort (August 26, 1819-December 14, 1861)
79. HM Queen Victoria of the United Kingdom (May 24, 1819-January 22, 1901)
80. = 78
81. = 79
82. = 32
83. = 33
84. HRH Duke Alexander of Württemberg (September 9, 1804-July 4, 1885)
85. Countess Claudine Rhedey von Hohenstein (September 21, 1812-October 1, 1841)
86. HRH Prince Adolphus, Duke of Cambridge (February 24, 1774-July 8, 1850
87. HRH Princess Adolphus, Duchess of Cambridge née HSH Princess Auguste of Hesse-Kassel (July 25, 1797-April 6, 1889)
88. George Bowes-Lyon, Lord Glamis (February 6, 1801-January 27, 1834)
89. Charlotte Bowes-Lyon, Lady Glamis née Miss Charlotte Grimstead (1797-January 19, 1881)
90. Mr Oswald Smith (July 7, 1794-June 18, 1863)
91. Mrs Oswald Smith née Miss Henrietta Hodgson (Dates unknown)
92. Lord Charles Cavendish-Bentinck (October 3, 1780-April 28, 1826)
93. Lady Charles Cavendish-Bentinck née Miss Anne Wellesley (1788-March 19, 1875)
94. Mr Edwyn Burnaby (September 29, 1799-July 18, 1867)
95. Mrs Edwyn Burnaby née Miss Anne Salisbury (1806-May 3, 1881)
96. George Spencer, 2nd Earl Spencer (September 1, 1758-November 10, 1834)
97. Lavinia Spencer, Countess Spencer née Lady Lavinia Bingham (July 27, 1762-June 8, 1831)
98. Sir Horace Seymour (November 22, 1791-November 23, 1851)
99. Lady Seymour née Miss Elizabeth Palk (died January 18, 1827)
100. Mr Henry Baring (January 18, 1776-April 13, 1848)
101. Mrs Henry Baring née Miss Cecilia Windham (February 16, 1803-September 2, 1874)
102. Mr John Bulteel (died September 10, 1843)
103. Lady Elizabeth Bulteel née Grey (July 10, 1798-November 8, 1880)
104. James Hamilton, 1st Duke of Abercorn (January 21, 1811-October 31, 1885)
105. Louisa Hamilton, Duchess of Abercorn née Lady Louisa Russel (July 8, 1812-March 31, 1905)
106. Richard Curzon-Howe, 1st Earl Howe (December 11, 1796-May 12, 1870)
107. Anne Curzon-Howe, Countess Howe née Miss Anne Gore (March 8, 1817-July 23, 1877)
108. George Bingham, 3rd Earl of Lucan (April 16, 1800-November 10, 1888)
109. Anne Bingham, Countess of Lucan née Lady Anne Brudenell (June 29, 1809-April 2, 1877)
110. Charles Lennox, 5th Duke of Richmond and Lennox (August 3, 1791-October 21, 1860)
111. Caroline Gordon-Lennox, Duchess of Richmond and Lennox née Lady Caroline Paget (June 6, 1796-March 12, 1874)
112. Mr Edward Roche (July 13, 1771-March 21, 1855)
113. Mrs Edward Roche née Miss Margaret Curtain (1786-January 21, 1862)
114. Mr James Boothby (February 10, 1791-October 28, 1850)
115. Mrs James Boothby née Miss Charlotte Cunningham (1799-January 22, 1893)
116. Mr John Wark (1783-April 16, 1823)
117. Mrs John Wark née Miss Sarah Duncan Boude (December 15, 1790-December 17, 1860)
118. Mr John Wood (July 29, 1785-January 29, 1848)
119. Mrs John Wood née Miss Eleanor Strong (ca. 1803-July 9, 1863)
120. Mr David Gill (Dates unknown)
121. Mrs David Gill née Miss Sarah Ogston (Dates unknown)
122. Mr William Smith Marr (November 27, 1810-February 13, 1898)
123. Mrs William Smith Marr née Miss Helen Bean (1814/5-July 20, 1852)
124. Mr William Littlejohn (August 12, 1803-July 8, 1888)
125. Mrs William Littlejohn née Miss Janet Bentley (January 26, 1811-October 1, 1848)
126. Mr James Crombie (January 13, 1810-January 31, 1878)
127. Mrs James Crombie née Miss Katharine Forbes (December 1, 1812-April 10, 1893)de:Ahnentafel

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