Ancestry

[Tautalus]

What is your theory for the story of your y-dna?

I don't exactly know how this haplogroup arrived in Portugal.
The ancestor clade (I-FT384439) belongs to a Frenchman, I don't know what region he is from. I imagine he is from northern France, since Globetrekker associates this region with his haplogroup.
My clade has 2 descendant clades. One (I-FTB15859) belongs to an individual from an unknown country, but with a Swedish surname (He participates in an FTDNA project). The other (I-FTB15686) belongs to two Germans from Schleswig-Holstein, in northern Germany, on the border with Denmark (They participate in an FTDNA project as well).
Globetrekker marks the coastal area from northern France to Denmark with blue shading, representing the expansion of the descendant clades. Personally, I think the expansion of the descending clades went in the opposite direction, from North to South. But regardless of that my ancient ancestor must have come from that area.
He could have been a Frank, an Anglo-Saxon, a Frisian. He may have come from Flanders, as you suggested.
He could have been a crusader or a settler who came to Portugal during the Reconquista period.
I doubt it came with the Suebi, they, like their Lombard cousins, must have belonged to the S2364 branch, which is the largest I2a2 subclade, not to my branch.
But the data I have is not sufficient to have a more concrete idea about all this.