"A typical pedigree chart provides a clean graphical representation of one's family tree, but it also occupies quite a bit of space to present the same amount of information as an ahnentafel."

AHNENTAFEL IS GERMAN for ancestor (ahnen) table (tafel). Preparing an ahnentafel chart is a very efficient way of organizing your pedigree chart in order to make it quickly understandable by others.
        On a standard pedigree chart, each person is assigned a number. These numbers are worth remembering since, if you follow the traditional numbering system, just by looking at a number you can know the relationship of any person on the chart to yourself. You are always 1, your father 2, your mother 3, paternal grandfather 4, paternal grandmother 5, maternal grandfather 6, maternal grandmother 7, patrilineal great grandfather 8, and so on in consecutive fashion.
        Using this system, one quickly notices some patterns. First, each new generation has double the number of ancestors of the previous generation. Thus you have four grandparents, eight great-grandparents, 16 great-great-grandparents and so on. By the 10th generation, you will have completed research on more than 1,000 ancestors; many will be unknown and others will be duplicates because of cousin intermarriage (it is estimated that before 1800 about 40 percent of marriages were between first, second or third cousins). Every father on your chart will have an even number and every mother will have an odd number that is her husband's plus one.
        Traditional pedigree charts usually print four generations to a page so that 16 generations usually take around four pages to display. The beauty of an ahnentafel is that these same 16 generations would fit on one page, depending on the type size chosen, and the same numbering system used in a standard pedigree chart again allows you to quickly discern your kinship with anyone on the ahnentafel.

Your Ahnentafel
The ahnentafel takes the numbering system described above and uses it to create a continuous list of ancestors instead of a chart. The format would be as follows:

1. your name
2. your father
3. your mother
4. your father's father
5. your father's mother
6. your mother's father
7. your mother's mother
8. your father's father's father
9. your father's father's mother
10. your father's mother's father
11. your father's mother's mother
12. your mother's father's father
13. your mother's father's mother
14. your mother's mother's father
15. your mother's mother's mother
16-31. your great-great-grandparents
32-63. your great-great-great grandparents

        An ahnentafel is particularly useful when you are corresponding with another genealogist in your family because indicating unknown ancestors with a blank space or line will allow them to see immediately where your genealogical research ends and, from the names and dates given, where you might have common ancestry.

Preparing an Ahnentafel

"Ahnentafels are a simple, non-graphical way of presenting one's family tree. Used well, they allow genealogists to perform some fancy mathematical tricks."

Most of the popular genealogy software programs have the ability to print out an ahnentafel. The most popular format for presenting genealogy data is the pedigree chart, but the simple beauty of an ahnentafel will no doubt appeal to many genealogists wanting a quick, simple view of their ancestry. Increasingly, software programs are offering hourglass charts, bow-tie charts and other picturesque and creative arrangements more notable for their novelty than for any intrinsic value. Set against these, the simple format of an ahnentafel and its superior way of organizing information in a numerically ascending lineal format that allows you to immediately identify your relationship to anyone on the chart is difficult to beat. Most software programs identify each person entered with a number or can be configured to do so.
        Knowing the numbers allows the researcher to use math to properly identify any individual in relation to themselves simply by knowing that even numbers are males and odd numbers are females, except for the first person who is always 1 whether male or female. Individual 33 is the wife of 32, or to put it in English your great-great-great grandparents, or to put it in ahnentafel language your father's father's father's father's father and your father's father's father's father's mother. Half 32 and get 16 who is your great-great grandfather. Add one and get 17 who is your great-great-grandmother; half 16 to 8 and you have your great-grandfather, and add one to get 9 who is your great-grandmother.
        It may help to have a doubling chart on hand when you get into the 15th and higher generations. A common shorthand trick is to refer to one's 15th-great-grandfather as "G15", but this could be misleading since you have over 16,000 grandfathers in the 15th generation, so let's simply refer to him by his unique ahnentafel number of 32768. It would require a thick binder to present this many fifteenth generation ancestors in conventional pedigree charts.
        While you may add other information to your ancestral ahnentafel listings other than number and name, in the interest of maintaining simplicity any added data should not take a listing beyond one line of data. It may take a while to get used to this numeric way of organizing ancestors, but it is a remarkably efficient system.

This article originally appeared in the November/December 2001 issue of Family Chronicle.