Reading Ahnentafels

An ahnentafel (German for “ancestor table”) is a compact way to display a persons direct line ancestor within a plain text format. Since there is no need for charts for software code, it is a helpful way to share ancestry information in emails or in a forum. With the ability to add attachments to emails, ahnentafels don’t seem to be used much today. Still, when you are doing genealogy research, you will come across them so it is a good idea to learn to read one.

Here is how a basic ahnentafel looks:

1. subject
2. subjects father
3. subjects mother
4. father’s father (your paternal grandfather)
5. father’s mother (your paternal grandmother)
6. mother’s father (your maternal grandfather)
7. mother’s mother (your maternal grandmother)
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
etc.

The numbering system is actually very simple. The subject on the ahnentafel is always number 1 – regardless on gender. After that, the subjects father is number 2 and the subjects mother is number 3. As the list progresses from there, the number for each persons father is their number times 2 and each persons mother is their number times 2 + 1. Other than the subject, even numbered people in the table are always male and odd numbered people are female.

Is you are having trouble visualizing how the numbers convey relationships, you can think of an ahnentafel as a pedigree chart written in list format.

— 4 paternal grandfather
|
|
— 2 father
|                    |
|                    |
|                     — 5 paternal grandmother
1 subject
|                     — 6 maternal grandfather
|                     |
|                     |
—3 mother
|
|
— 7 maternal grandmother

Notice that the numbering of the pedigree chart is the same as the ahnentafel. The number of the father is 2 times that of the child and the mother’s number is 2 times + 1. Males are even numbers and females are odd numbers (except the subject who can be male or female).

Here is a portion of real ahnentafel that we can use to learn more:

1. Barack Hussein Obama, Jr. (1961)
2. Barack Obama (1936-1982)
3. Stanley Ann Dunham (1942-1995)
4. Onyango Obama (1895)
5. Akumu
6. Stanley Dunham (1918-1992)
7. Madelyn Lee Payne (1922)
8. Obama, of Kendu Bay, Kenya
9. Nyaoke
12. Ralph Waldo Emerson Dunham (1894-1970)
13. Ruth Lucille Armour (1900-1926)
14. Rolla Charles Payne (1892-1968)
15. Leona McCurry (1897-aft1930)
16. Obiyo
24. Jacob William Dunham (1863-1936)
25. Mary Ann Kearney (1869-1936)
26. Harry Ellington Armour (1874-aft1930)
27. Gabriella Clark (1877-aft1930)
28. Charles T. Payne (1861-aft1920)
29. Della Wolfley (1863-aft1900)
30. Thomas Creekmore McCurry (1850-1939)
31. Margaret Belle Wright (1869-1935)
32. Okoth
48. Jacob Mackey Dunham (1824-1907)
49. Louisa Eliza Stroup (1837-1901)
50. Falmouth Kearney (1830-1878)
51. Charlotte Holloway (1833-1877)
52. George W. Armour (1849-aft1890)
53. Nancy Ann Childress (1848-1924)
54. Christopher Columbus Clark (1846-1937)
55. Susan C. Overall (1849-bef1920)
56. Benjamin F. Payne (1838-1878)
57. Eliza C. Black (1837-1921)
58. Robert Wolfley (1834-1895)
59. Rachel Abbott (1835-aft1900)61. Elizabeth Creekmore (1827-1918))
62. Joseph Samuel Wright (1819-1894)
63. Frances A. Allred (1834-aft1880)
64. Obongo
96. Jacob Dunham (1795-1865)
97. Catherine Goodnight (1794-aft1870)
98. John Stroup (c1814-1851)
99. Eliza Jane Clemmons (c1816-1882)
100. Joseph Kearney (c1794-1881)
101. Phoebe Donovan
102. Josiah Holloway (1804-1887)
103. Martha Mallow (1810-1888)
104. William Armour (c1812-aft1880)
105. Sarah Poland (1824-aft1880)
106. John Milton Childress (1816-1866)
107. Nancy Conyers (1823-1860)
108. Thomas Clark (1812-1892)
109. Elizabeth Davis (1822-1900)
110. George Washington Overall (1820-1871)
111. Louisiana Duvall (1826-1855)
112. Francis Thomas Payne (1794-1867)
113. Harriet Bowles (1806-1857)

Notice that if a name is unknown the number should be skipped to keep the relationships correct. For example in Barack Obama’s ancestry numbers 10 and 11are unknown and skipped.

Suppose we want to find Madelyn Lee Payne’s mother’s name. Take her number (7) and multiple by 2 to get 14. Then, since we are looking for her mother’s name, we add 1 to get 15. So, Leona McCurry is the mother of Madelyn Lee Payne. Easy right?

While we could find any relationship by tracing through the table one generation at a time like we just did, there is an easier way that is less prone to error.

To find the relationship between the subject and any other person in the tree, we can repeatedly divide by 2. So, to learn the relationship between Barack Obama (1) and Thomas Clark (108) start out by seeing if the higher number is even or odd. Since it is even, just divide it by 2 and write father.

108/2=54
father

Repeat that process using the number we just got.

54/2=27
father

Now we have an odd number as a result. We know that odd numbered people are female so this time we will subtract 1 from the number and write mother.

27-1=26
26/2-13
mother

Continue this process until you get to thethe subject.

108/2=54 54/2=27 (27-1)/2=13 (13-1)/2=6 6/2=3 (3-12)/2=1
father       father      mother         mother      father  mother   subject

Now, write a relationship statement by reversing the list:

Thomas Clark is Barack Obama’s mother’s father’s mother’s mother’s father’s father.

We could also say that Thomas Clark is Barack Obama’s 4th great grandfather but, so are 31 other men. Only one of them is his mother’s father’s mother’s mother’s father’s father though.

This post has only explained the basics of ahnentafels and I know they look intimidating at first. Spend some time working with them and they will soon become a lot less mysterious.

In my next post, I will show how to use binary numbers as an alternate way to decode ahnentafels.