Ahnentafel
What are Ahnentafel?
Like so many other words borrowed from languages other than English, the meaning we attach to Ahnentafel is not the one it represents in the original source. To a German family historian an Ahnentafel is literally a "table of ancestors" (or pedigree). As part of that table, each of the person's direct ancestors is assigned an ancestor number (Vorfahrennummer). The rules for assigning those Vorfahrnnummer were first spelled out in 1590 by an Austrian genealogist called Michaël Eytzinger.
This numbering method proved so successful that it was adopted by English speakers for their pedigrees (or trees), But instead of simply calling them Ancestor numbers, or Eytzinger numbers or even Vorfahrennummer, we named them Ahnentafel (which must be very confusing for German speakers).
You can view an Ahnentafel (in the German sense) for the current Queen of England which includes (on each line) the Vorfahrennummer that we would call the Ahnentafel.
How are they assigned?
The three most important rules for assigning Ahnentafel are that you must specify the reference person in advance, then work backwards in time from that person, and that only direct ancestors get a number. So if I am the reference person (shown as 1 on the left below), my parents have numbers (2 and 3) but my daughter cannot have an Ahnentafel and nor can my uncle or even my wife(because none of them is my ancestor). But if you switch the focus to my first cousin (as the new reference person on the right), her father has a number but his brother (my father) does not (and nor do I). Of course our common ancestors (grandparents) have a number assigned in each case.
Like so many other words borrowed from languages other than English, the meaning we attach to Ahnentafel is not the one it represents in the original source. To a German family historian an Ahnentafel is literally a "table of ancestors" (or pedigree). As part of that table, each of the person's direct ancestors is assigned an ancestor number (Vorfahrennummer). The rules for assigning those Vorfahrnnummer were first spelled out in 1590 by an Austrian genealogist called Michaël Eytzinger.
This numbering method proved so successful that it was adopted by English speakers for their pedigrees (or trees), But instead of simply calling them Ancestor numbers, or Eytzinger numbers or even Vorfahrennummer, we named them Ahnentafel (which must be very confusing for German speakers).
You can view an Ahnentafel (in the German sense) for the current Queen of England which includes (on each line) the Vorfahrennummer that we would call the Ahnentafel.
How are they assigned?
The three most important rules for assigning Ahnentafel are that you must specify the reference person in advance, then work backwards in time from that person, and that only direct ancestors get a number. So if I am the reference person (shown as 1 on the left below), my parents have numbers (2 and 3) but my daughter cannot have an Ahnentafel and nor can my uncle or even my wife(because none of them is my ancestor). But if you switch the focus to my first cousin (as the new reference person on the right), her father has a number but his brother (my father) does not (and nor do I). Of course our common ancestors (grandparents) have a number assigned in each case.
The reference person is always assigned the Ahnentafel "1", regardless of whether that person is male or female. After that every male parent has an Ahnentafel double that of his child (so always an even number) and every female parent has an Ahnentafel one greater than that of her male partner (so always odd).
In mathematical terms if a person has Ahnentafel = n, then his father is 2n and his mother 2n+1.
In mathematical terms if a person has Ahnentafel = n, then his father is 2n and his mother 2n+1.
Of course, when I move the focus to my daughter, all the numbers change.
Her mother is now a direct ancestor of the focus person and so gets a number. My parents are my daughter's grandparents and their changed numbers reflect that. As do the numbers assigned to the previous generation. Note that this chart does not include a symbol for the people who would (now) have Ahnentafel 6 and 7. Who are they? |
Why use them?
The advantage of using Ahnentafel can be seen if you consider my relationship to my father's mother's father's father's mother. I could describe her as my great great great grandmother (but I actually have sixteen 3xgreat grandmothers, so there is room for lots of confusion). Or I can say that she has Ahnentafel 41 with respect to me (which identifies her exactly).
Calculating that value of 41 is surprisingly straight forward so long as you apply the three rules (1, x2, x2+1) correctly when translating words into numbers.
The advantage of using Ahnentafel can be seen if you consider my relationship to my father's mother's father's father's mother. I could describe her as my great great great grandmother (but I actually have sixteen 3xgreat grandmothers, so there is room for lots of confusion). Or I can say that she has Ahnentafel 41 with respect to me (which identifies her exactly).
Calculating that value of 41 is surprisingly straight forward so long as you apply the three rules (1, x2, x2+1) correctly when translating words into numbers.
Turning an Ahnentafel back into a verbal description seems more complicated but you simply follow the same rules in reverse order to decide on the relationship respresented by an Ahnentel of 90. Odd and even numbers tell you the sex of the person and to move forward a generation divide (the number of the male parent) by 2
Now read up the list to get the result: 90 is the focus person's father's mother's mother's father's mother's father. Of course you could also say 4xgreat grandfather (correct, but one of 32 who fit that description), or even paternal grandmother's maternal grandfather's maternal grandfather (but that would be showing off!).
Ahnentafel in Lost Cousins
Because the Lost Cousin's database asks you to assign Ahnentafel to each of your direct ancestors, it provides you with a handy chart (https://www.lostcousins.com/pages/info/lostcousins_chart.pdf) to check your calculations. Remember that Lost Cousins does not ask you to give Ahnentafel for blood relations or those joining the tree by marriage (because only Vorfahr - direct ancestors - can have a Vorfahrnummer).
Ahnentafel in Lost Cousins
Because the Lost Cousin's database asks you to assign Ahnentafel to each of your direct ancestors, it provides you with a handy chart (https://www.lostcousins.com/pages/info/lostcousins_chart.pdf) to check your calculations. Remember that Lost Cousins does not ask you to give Ahnentafel for blood relations or those joining the tree by marriage (because only Vorfahr - direct ancestors - can have a Vorfahrnummer).
If you have completed the exercises in the Tween-meeting News of 19 August 2019, then you check your solutions on the linked page.