Presentation of Family Tree Charts

For many people, the centrepiece of family history research is a family tree chart—the culmination of the hard work to find the information and a visually pleasing document to behold and display.

Whilst the above is true, family charts also need to play a functional role: they are the means by which the connections between generations are communicated and navigated. In the same way that a graph helps communicate numeric data, family tree charts communicate genealogical information.

Having worked with many clients over the years, they often go on a journey in regard to what they want from family tree charts. The initial expectation is that they want a vast family tree, showing everyone, but as they learn more about their ancestors, they tend to realise that a set of well thought-out charts are far better at understanding their relations and are also more visually pleasing; they also discover that different kinds of charts are best suited for various tasks.

In mathematics and statistics, there are different kinds of graphs and charts: Line Graphs, Bar Charts, Pie Charts, Histograms, Scatter Plots, Venn Diagrams, Area Charts, Spline Charts, Box and Whisker Charts, etc… In genealogy, we have different kinds of charts too, although they can be split into two broad camps: ancestors or descendants. Ancestor charts start from someone and work backwards; Descendant charts start from someone and work forward. They can be mixed in limited circumstances, but just as combining a bar chart and a pie chart would likely make both harder to understand, so does mixing ancestor and descendant charts. Usually, the information is better considered as two charts, rather than as a single chart.

One of the biggest problems that makes charts hard to understand is when connecting lines cross. Only a few aren’t a problem, but the more there are, the more spaghetti like a chart becomes.

Ancestor Charts

These start from a person, usually someone alive today, and work backwards, showing their parents (2), grandparents (4), great grandparents (8), great, great grandparents (16), etc. They don’t show their aunts, uncles, cousins, great aunts and uncles, as this data would be too confusing. On a technical level, to add these other relatives would mean that many of the connecting lines would have to cross one another.

Descendant Charts

These start from an ancestor, or sometimes an ancestral couple (usually placed at the top of the chart), and work forward, showing their descendants, at least along the lines being investigated. This kind of chart is what most people, at least in Britain, would think of as a traditional family tree and sometimes called a drop-line pedigree chart. This kind of chart does show siblings, aunts, uncles, cousins (at least to the degree to which they have been researched), but only those who are descended from the ancestral starting point.

In the strictest traditions, descendant charts would only follow the male lines forward; when a lady married, her children would be shown on her husband’s family chart. This has the side effect that the main people on this chart would usually share a birth surname, or married someone with that surname. Whilst this is old-fashioned, it does enable a chart to be grouped in a logical way, i.e. by surname.

When considering any individual, they would have a range of descendant charts one which they had ancestors, most closely, their mother’s and father’s charts, but of also those of their grandmothers and beyond.

With the exception of cousin marriages, which were once quite common, by starting with a single ancestor (or couple) and working forward, their should be no crossing lines.

There are several “rules” with drop-line charts, that are generally applied:

  1. Children should be placed in birth order, left to right. In very old charts, all the boys were placed first, then the girls, as in peerage families the girls didn’t inherit until there were no surviving sons, but quite rightly, that sort of attitude has gone.
  2. Husbands are usually placed to the left of their wives, unless there is more than one, in which case the wives would flank him on either side.
  3. All descendants at the same level should be on the same row of the chart. This helps to prevent confusing of a cousin with an aunt or uncle.
  4. Family charts should contain the right level of detail. Lots of information is better provided in narrative form, but there should be enough to help distinguish each person and have the key details about their lives.
  5. Uncertain information shouldn’t be shown as certain. For example, charts should contain question marks or dotted lines if some fact or relationship hasn’t been proven.

These rules can be broken in some circumstances. For example, sometimes for the sake of space, a more pleasing chart could result if rule 1 (ordering of children) is broken, but under such circumstances, it would be usual to place numbers next to the children to show that the birth order is

There are also some softer rules, which are perhaps a matter of taste:

  1. Boxes shouldn’t be drawn around each person. A lot of modern computer software does this, but—in the author’s opinion—this clutters a chart (few professional trees would include boxes around each person).
  2. Use of fonts and colours should be limited and carefully chosen. Many computer programs generate charts that don’t make the most tasteful choices in regard to use of colours and fonts.
  3. A chart shouldn’t be too big or too small. Sometimes it is better to break a rule to create a more visually pleasing chart overall, rather than stick strictly to one of the defined rules. This can be taken to an extreme, a chart that is too small, or broken into too many pieces can also be too hard to understand. Often a human, rather than a computer, is better placed to decide how big a chart should be, and which rules should, or shouldn’t be broken, to create a chart that.

You may thing from the soft rules above, that I am anti the use of computer software when creating family tree charts. The reverse is actually true; I have written my own computer software which I use to create my family charts, but which allows better customisation and layout of trees than the commercially available software. I will perhaps look at some of these design choices in future blog posts.


Lynskey, M. (1996), Family Trees, A manual for their design, layout & design, Phillimore & Co. Ltd.
McLaughlin, E, (1996). Laying Out A Pedigree, McLaughlin, (2nd Ed.)
Herber M. (2005), Ancestral Trails, (2nd Ed.) Sutton Publishing