On Tuesday, September 5, 2017 at 4:25:00 PM UTC-7, Peter Stewart wrote: > In view of this, it would be interesting to know what proportion of > American 'gateway' ancestors traced at least to the mid-14th century did > not have a known line to Edward III. > > Peter Stewart One possible answer to Peter's question might be provided by Douglas Richardson's "Plantagenet Ancestry". Of the roughly 150 surnames of gateway ancestors (excluding siblings) covered in at least the 1st edition of that work, only slightly more than half have descents from Edward III. The remainder derive their Plantagenet descents from an earlier monarch - or from a non-monarch Plantagenet descendant (e.g., Hamelin Plantagenet). Make of that what you will... :-)