Most of us don’t create any kind of system to number our ancestors. Luckily, today, our software programs do all the fancy numbering for us, although each program has its own system.
However, when we venture to books of family histories and professional journals, readers will come across several different numbering systems, each devised to make tracing specific lines much easier.
What styles might we find?
The simplest style is one of the oldest – the Ahnentafel.
The beginning person in the tree is 1. That person may be ourselves or any single person in our tree who we want to split off into a simpler tree.
For example, in my ahnentafel, I’m 1, my father is 2, my mother is 3, my paternal grandparents are 4 and 5 and my maternal grandparents are 6 and 7.
If I wanted to identify my DAR patriot ancestor, Joses Bucknam, as #1 and then want to create an ahnentafel for him, his parents would be 2 & 3, his grandparents would be 4, 5 and 6,7, and so on.
The ahnentafel is the only system that begins with the latest ancestor and numbers back in time.
The other ancestor numbering systems begin with the earliest known ancestor and come down in time to the present.
The Henry System begins with “Ancestor” as 1. His children would then be designated as 11, 12, 13, which mean the oldest child of Ancestor 1, the second oldest child of Ancestor 1, the third oldest child of Ancestor 1, etc. The grandchildren would be numbered 111, 112, and so on.
111 represents the oldest child of the oldest child of Ancestor 1 or, in simpler terms, 111 would be the first born grandchild.
The d’Aboville System is virtually the same as the Henry System, but it uses periods to denote and separate each generation. Therefore, we would have Ancestor 1 followed by 1.1, 1.2, 1.3 for the first, second and third born children of Ancestor 1. Grandchildren would be designated by 1.1.1, 1.1.2, 1.1.3 and so on.
The next system is the National Genealogical Society Quarterly System (NGSQ), which again begins with Ancestor 1, but then continues to number all the children, grandchildren, etc. with sequential numbers. So, if Ancestor 1 had six children and three grandchildren, they would all be numbered in birth order as 1, 2, 3, 4, 5, 6, 7, 8, 9, 10. [Note: One difficulty with this system is finding unexpected children. What happens to the numbering if it is discovered that Ancestor 1 had a second wife who gave birth to a known child? That child would become #8 and the numbering for all the grandchildren, greats, etc. would be wrong.]
The last system is that of the New England Historical Genealogical Society journal, The Register. Register style also assigns the first detailed ancestor as Ancestor 1. The children are designated by Roman numerals – ii., iii., iv, v, etc. When a child is also treated in the article, a number 2 is added to the left margin. Children about whom nothing else is being written remain solely with their Roman number.
This style is a harder one to visualize, so here is a crop of one family:
The children at the top are the grandchildren of Ancestor 1, John Bond. They are the children of Ancestor 1’s son, Edward. In addition, Register style adds the male line in parentheses after each ancestor whose family is being treated, e.g. “3. Edward (Edward2, John1).
“3. Edward” is further identified as the son of Edward2 and grandson of John1.
These are simplified explanations of each ancestor numbering style, but it is detailed enough for readers to navigate family trees.
If you are considering writing an article or book for publication, I recommend looking further for more detailed instructions to decide which style you would prefer to use or which style is required.