All my known ancestors (some back to the 1500's) were from the United Kingdom, so making a pie chart illustrating just this is pretty uninteresting: a single whole pie of 100% UK. Many other people have much more variable and exotic ancestral origins. However, on coming across an Excel spreadsheet with Ancestry Pie Charts created by John Tierny (under a Creative Commons license), I had another idea: to split up my ancestry into countries within the UK where my ancestors originated: England, Wales, Scotland, and the Isle of Man (the Isle of Man is strictly a Dependancy of the UK) – or to subdivide further by county. I originate from 10 counties/areas + one Unknown (see My Brick Walls and last blog posting on Frederick Woolfall and the Diamond Ring "Hush Money"): 18.75% from Lancashire; 12.5% each from Anglesey, Caernarvonshire, Cumberland, and Shropshire; 9.375% from Devon; 6.25% each from the Isle of Man and Unknown (probably Lancashire or somewhere else in the UK); and 3.125% each from Cornwall, Selkirkshire, and Dumfries-shire. But all of these 11 counties with similar-sized "slices" seemed like too much granularity for pie charts, so I opted to use countries within the UK.
With John Tierny's spreadsheet, you fill in the ancestry of all 16 of your 2nd great-grandparents, and everything forwards is calculated automatically from there. There are columns for up to 10 "regions", and these can be customized (don't miss the note in the Info. on the 1st worksheet for how to unprotect the worksheets, which allows for customization). My pie charts are shown below. I tweaked a few things on the original spreadsheets to have colours and formatting to my liking, and added some drop shadows to the pie charts.