County conundrum

[les.the.paperman]

I have, among my DNA matches, one that says that we are 5th-8th cousins. We share the same family name. We've been in touch but can't begin to work out the connection. He has a tree going back more than 12 generations, all in the same county, Northamptonshire.
I can't go back quite so far, at least not on my own family name because of an illegitimacy issue that comes up, but the name is/was quite a common one in Norfolk and Suffolk since the 1600-1700s, especially crossing back and forth across the county boundary, which is the area to which I'm connected. I feel that I should be able to find an interloper at my end but, no luck.

5th-8th cousins connections should surely show up within his 12+ generations but he cannot find anyone that moved eastwards. I can't find anyone at my end that has moved the same direction. Where do we begin? Any ideas?

 

[Tim]

Hi Les,

How many cM's do you share? You should also be aware that even though you share the same surname, that doesn't necessarily mean that is where the common ancestor lies. Do you have any shared matches?

 

[peter]

Someone who Ancestry suggest might be a 5th to 8th cousin could be much more distant. We have far more very distant cousins than distant cousins - indeed once you get beyond 10th cousin we're all related (see the table in my Masterclass).

 

[les.the.paperman]

Hi Les,

How many cM's do you share? You should also be aware that even though you share the same surname, that doesn't necessarily mean that is where the common ancestor lies. Do you have any shared matches?

Shared DNA: 6 cM across 1 segments and no shared matches. A very small amount and, of course, you're right, it may not be the family name that produces the match. I should have thought of that myself. I'll just keep looking everywhere but anything that might break my illegitimate brick wall immediately sounds an alarm bell.

Thanks