One Fleming in 30 to 40 Generations and you think that might make a difference ? There been Romans, English, Vikings, Normans wandering around Wales.
Since Celts roamed over most of Europe at one time or another what was he descended from? The chances of anyone being pure bred is very slim in Europe, even being a pure bred Homo Sapian is now thought to be less possible.
"We make a living by what we get, but we make a life by what we give"
Sir Winston Leonard Spencer-Churchill