Surprisingly strong DNA link with Norwegian.

[Catservant]

Hi. I have no known Norwegian links in my family tree. However I have many Norwegian and Swedish DNA matches.
I have been contacted by a Norwegian with Norwegian family tree asking me if I have Norwegian links.
We share 165.5 cm in 9 segments with the largest being 30.1 cm. This could make us about 2nd cousins which I can’t account for in my tree.
The only uncertain part of my tree is a Cornish illegitimate 4 times great grandfather, born about 1800. He was christened with the middle name Tonsson which sounds Scandinavian to me.
 Is it possible that I could share this much DNA with someone who shares a 5 times great grandfather with me? Otherwise, I presume there is an illegitimate ancestor somewhere in our trees.

[melba_schmelba]

Hi. I have no known Norwegian links in my family tree. However I have many Norwegian and Swedish DNA matches.
I have been contacted by a Norwegian with Norwegian family tree asking me if I have Norwegian links.
We share 165.5 cm in 9 segments with the largest being 30.1 cm. This could make us about 2nd cousins which I can’t account for in my tree.
The only uncertain part of my tree is a Cornish illegitimate 4 times great grandfather, born about 1800. He was christened with the middle name Tonsson which sounds Scandinavian to me.
 Is it possible that I could share this much DNA with someone who shares a 5 times great grandfather with me? Otherwise, I presume there is an illegitimate ancestor somewhere in our trees.

This wouldn't be with MyHeritage would it ?? MyHeritage is somewhat notorious for giving lots, if not, most Brits lots of mysterious Scandinavian relatives who seem to be fairly close...but probably aren't. Possibly to do with imputation they use to match between different chipsets of different companies kits that are uploaded. Someone did a survey of how many matches on MyHeritage might be false, I think below about 24cM, and the % was fairly high (they compared matches of children and parents). Matches with small largest segment below 12cM are probably also dubious.

[Biggles50]

I would not put a lot of reliance on any ethnicity estimate.

My Heritage DNA test says I have 34.2% Scandinavian ethnicity yet my tree going back 300 years has ZERO ancestors from anywhere other than England, Ireland and Wales with the exception of the line going back from my 2x Great Grandfather who was Italian.  So where the high percentage of Scandinavian comes from in My Heritage is another matter and by comparison my Ancestry DNA test now gives 5% Norwegian.

[Rena]

I haven't taken a DNA test but it seems that the genes are giving credence to our school teacher who taught us about the Vikings (Norwegians and other Scandinavians) invading Britain.

We were taught about King Cnut/Canute turning back the tide.  Additionally the number of Norwegian sailors who married local girls in the port of Hull was quite common according to census that I've seen.

https://en.wikipedia.org/wiki/Cnut

[Gadget]

I would not put a lot of reliance on any ethnicity estimate.

I've always been sceptical but now I think they're just playing Globle with us!

[Stanwix England]

Normally I wouldn't put lots of faith in the ancestry estimates.

However, given that you seem to have lots of DNA matches actually from Norway, that does seem to suggest that there is some truth in the matter, in this particular case.

[melba_schmelba]

Normally I wouldn't put lots of faith in the ancestry estimates.

However, given that you seem to have lots of DNA matches actually from Norway, that does seem to suggest that there is some truth in the matter, in this particular case.

The problem is so does everyone else (on MyHeritage), at least Brits and Irish. May be picking up on IBD or IBS segments, or it may be down to imputation causing many false matches. I think the level of false matches that someone found on MyHeritage was about 1/3 below 24cM.

[Rena]

My Heritage DNA test says I have 34.2% Scandinavian ethnicity yet my tree going back 300 years has ZERO ancestors from anywhere other than England, Ireland and Wales with the exception of the line going back from my 2x Great Grandfather who was Italian. 

We've had genes longer than 300 years   

. "The earliest Viking raid on Spain took place in the year 844. A Norse fleet with its blood red sails landed in Galicia after sacking Bordeaux, and proceeded to plunder the coastal villages until they were halted by the troops of King Ramiro I of Asturias near A Coruña on the northwestern coast of Galicia ..."

Those darned Vikings went everywhere - the Arabs wrote that the strangers were as big as trees.  Unbelievably they also landed in the Americas.

I doubt that any young lady was safe when the Viking sailors landed.

[RobertHauteville]

There has been a long trickle of Norwegians "moving south" who mainly settled in the Highlands, over to the west and down. The Dublin Vikings included Norwegians and they raided/settled Wales, Gloucestershire & Cornwall.

Surnames are relatively recent so "Tonsson" may be strong clue. In England and Wales patrynomic names end in "s" whereas in Scotland and Scandinavia they end with "son", i.e.
 
England/Wales : Jones/Johns        Scotland : Johnson
England/Wales : Williams               Scotland : Williamson
England/Wales : Roberts                Scotland : Robertson

If a Norwegian fisherman/sailor/merchant migrated to Scotland they could easily have had a descendant who sailed around the coast to Wales or Cornwall.