This is a MUCH more controversial idea than pop-history would have you believe. There have been Viking women found buried with weapons and armour; however, there are also men who weren't warriors found buried with arms and armour as well. Scholarship on the matter isn't really sure if the women found buried that way were warriors being honored as such, or rich/wealthy/politically powerful people who were buried in the trappings of a martial society. Also, the extrapolation of "a shockingly small number of women were buried with swords" to "the Vikings had gender equality and badass warrior women in every port" is great Netflix fodder, but not really backed up anywhere else.
>Never mind of course that vikings weren't big on "consent" or that they're darlings of far right groups.
Vikings also literally had a slave based economy; the only thing that got the various Anglo-Saxon kingdoms to unite was "hey, we don't want to be slaves/the main event of excruciatingly brutal human sacrifices."
>compared to those awful Anglo-Saxon Christians
Interestingly enough, almost all the Vikings converted peacefully to Christianity within a decade or two of settling in Britan.
Compare: "Those evil germanics who sailed up the Volga and subjugated our ancestors, you know how much silver they took home? And you've seen how wealthy Copenhagen is now? My buddy Igor ran the numbers, and compound interest explains it all!". That's not a speech which will improve your political career in Russia.
Direct records of ancestry are too scattered to piece together long timescales. What he (and collaborators) do is to find very rare surnames, in records at some distant time (e.g. Oxford graduation in 1600, high-status, or common criminals executed then, low-status) and then trace look for the same name in later data (e.g. Victorian wills, or today's tax data). Rare names give you a fairly targeted marker. One which the carriers are often unaware of.