1, 2, 3 . . . it’s an ahnentafel!

Penny at podium_croppedA friend recently received a document from a cousin, outlining her family’s ancestry. It was quite long, she said, and mentioned a Mayflower ancestor — but she didn’t know how to interpret it. There were lots of numbers, some of them roman numerals.

My well-trained husband, hearing this, asked, “Is it an ahnentafel?” It sounded like it might be. I asked one more question: does it start in the past, or does it start at or near the present? “It starts with me, as number 1,” my friend said. “Ah, yes,” I said, “it is an ahnentafel.”

The ahnentafel, or ancestor table, lists your direct line of ancestors, beginning at or near the present and going back to the earliest known ancestors. I like to think of it as a multigenerational, or pedigree, chart turned sideways: the main person is at the top instead of at the left. Each generation doubles in size.

In an “AT,” the numbering system is the key to determining relationships. Let’s say we’re tracing all your ancestors. You are person number 1. Person 2 is your father and 3 is your mother. Men’s numbers are always even, and women’s numbers are always odd. To determine the number of a person’s father, multiply the person’s number times 2. To determine the number of the person’s mother, add 1 to the father’s number.

Thus your paternal grandfather is 2 x 2 = 4 and your paternal grandmother is (2 x 2) + 1 = 5; your maternal grandfather is 3 x 2 = 6, and (3 x 2) + 1 = 7, your maternal grandmother. The farther back in time, the higher the number. Generation 2 (your parents) has only two people; generation 3 has four; generation 4 has eight; generation 5, sixteen; and so on—until in generation 10 you are up to number 512. It’s not unusual for an AT to have thousands of numbers. That’s where the math becomes helpful. (If you want to list children under each father-mother pair, you would do so with lower-case roman numerals, as my friend’s cousin did.)

You can, of course, go the other way in figuring relationships: to find the child of someone, divide the father’s number by 2. For example, my friend’s AT listed a Mayflower ancestor, Francis Cooke. On her chart, he was no. 14890. To trace her descent from him, she would begin by dividing Francis’s number by 2, and go from there:

14890 / 2 = no. 7445, Hester Cooke, married to no. 7444, Richard Wright.

7444 / 2 = no. 3722, Adam Wright.

3722 / 2 = no. 1861, Mary Wright, married to no. 1860, Jeremiah Gifford.

And so on, back to 3, 2, 1. My friend’s mother, her father, and herself.


About Penny Stratton

A veteran of the book publishing industry, Penny Stratton retired as NEHGS Publishing Director in June 2016; she continues to consult with the Society on publications projects. Among the more than 65 titles she managed at NEHGS are The Great Migration Directory, Elements of Genealogical Analysis, Genealogist’s Handbook for New England Research, and the award-winning Descendants of Judge John Lowell of Newburyport, Massachusetts. She has written for American Ancestors magazine and is a regular poster on Vita Brevis. With Henry B. Hoff, Penny is coauthor of Guide to Genealogical Writing: How to Write and Publish Your Family History; she is also the author of several Portable Genealogists on writing and publishing topics.

12 thoughts on “1, 2, 3 . . . it’s an ahnentafel!

  1. Thank you, Penny! This is my favorite kind of family tree. I have done one for each of my grandparents, beginning each as #1. When I mention Ahnentafel to people, I am met with silence or blank stares; most family researchers seem never to have heard of this wonderful layout/tool. Perhaps one must be a “numbers person” to really appreciate it!

  2. Wow….I would be one of those with the blank stare. Thanks for enlightening and expanding my knowledge. Best Regards, Robert Alden Griffin – from John Alden/Priscilla Mullins.

  3. Thanks! I tried to do an ahnentafel years ago to join the Denison Society, but had just started genealogy and gave up. My tree is now complex enough that one would really be helpful. I appreciate being reminded of the possibility.

  4. My favorite, too! Much used by Scandinavians who call it “Ahnentavle”; both words mean Ancestor Table. The numbering system should be familiar to anyone who had done a pedigree chart.

  5. Penny, Thank you for writing this article on the ahnentafel. After 52+ years of gathering genealogical materials on my family and after publishing several books and pamphlets on branches of the family, I finally decided several years ago to organize all the research into an ahnentafel form. During the past three years, I have both written the ahnentafel and have been preparing biographical sketches with footnotes of each ancestor. Although there are many biographical sketches to prepare, I have finished 678 sketches from my parents back several generations. My work continues daily on these biographies and, in the meantime, the sketches are being printed for notebooks for my children and nieces and nephews. I highly recommend this format for genealogical records.

    1. I have been dithering for a long time about how to include my sometimes lengthy notes in the family tree and you have decided it for me – ahnentafel wins. I have no intention of publishing for the general public, just family. By the way, I am descended from Robert Hawkins via Zachariah and wonder if any of your sketches would provide data concerning my line, which peters out with Levi Hawkins who had a daughter Jane with Gertrude Reynolds. The origins of Gertrude are unknown, at least by me! Family lore claims she was descended from a brother of Sir Joshua Reynolds but there is no proof that I can find.

      1. You will be very happy with your work on ancestral biographies. Like you, I struggled with the cost of arranging each person in a family genealogy and to include all the pictures, maps, documents, news clippings. Now, with a biographical of each ancestor, I can include so much more documentation. Each day I spend time on each sketch, finalizing language, footnotes, illustrations, etc. Today I just finished a 14 page summary of one ancestor. With regard to the Hawkins family, although I have built a fairly large library on the Hawkins family, my line descends from Michael Hawkins, Loyalist from New Jersey to New Brunswick in 1783, but I have not been able to connect him with his parents. Wish I could be of asssitance.

  6. I use Ahnentafel numbers to keep my hard copy file folders–one for each direct ancestor couple–in order. I’d like to find software that will print a “bare bones” Ahnentafel, listing only direct ancestors (i.e. with none of the great-uncles, great-aunts, etc.). This would provide a quick index to my direct line file folders, and, by not printing out everyone, save paper. So far I’ve not found a program that will do this without me telling the program one by one which names to delete. Does anyone have genealogy software that will do this? My FTM will print an Ahnentafel, but not this “bare bones” sort.

  7. I’ve found the Ahnentafel to be an excellent way to organize my thoughts (as well as my tree). Two names jumped out at me: Francis Cooke is my eleventh great-grandfather, and I have many Giffords as well. Looks like your friend and I are distant cousins!

  8. I’m currently blogging my ahnentafel one person at a time. It’s been helpful in focusing my research and making me dig out all the children and grandchildren I can. I didn’t know about the Roman numeral numbering, but it makes sense. http://dedpepl.blogspot.com

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