We now have a deep ancestry capability as a result of DNA which will spell out the arrival of the Darlington Derlingtun, de Derlington, de deornoth,etc which are people who carried our name in it's earliest form in England Scotland and Ireland.
I have been researching the depp ancestry and at this point in time have estabished that the Darlingtons may have been original Britons. Further testing will could bear this out.
So far we are with 5,000 to 6,000 years ago and as more results come in we will be able to all benefit. This is at a time when surnames did not exist. We need to get to within 800 years ago and it wont take long once more Darlingtons determine the generations of dads through their Y-DNA
What would be helpful is to undertkae the national Geographic's Genographic DNA test. It's cheap and will help very much in Darlingtons wherever they live in the world to find the Darlington common ancestor.
If you need to know more pease contact me on firstname.lastname@example.org