Frisian isn't as close to (modern) English as some people seem to think

[LightHouse89]

that language sounds like a combination of various Germanic languages ​​-Pan Germanicus language

Nope. It is old Saxon basically. However I tend to think English is a cross between Frisian and Danish.

[Sisak]

it also sounds like German to me

[Dombra]

I understand it better than Dutch

I have always thought Dutch to "cluster" inbetween German and English (closer to German though). Frisian is the "missing link" that is closer to English

[Hevo]

It is very possible that Batavians could have had some status and prestige among Germanic peoples in the region for their role inside the Roman military.
Interesting is their rebellion, for sure some where exiled or left voluntarily after it, they could have moved with the Frisians and Saxons or even in Scandinavia.

The Batavians probably moved with the Salian Franks.

[kkk77]

I can understand Europe.

[Jackson]

One interesting thing to consider genetically is the relatively low levels of R1a in most areas of England (even the east, where it averages about 5%), as not only is R1a lower in the Netherlands than in nearby parts of northern Germany and Denmark, but there is also a correlation between low levels of R1a and coastal areas along this part of the coast (old Frisian areas). So perhaps a large amount of Frisians or coastal Germans with lower amounts of R1a compared to their inland and more north-eastern neighbours being involved in quite a way would help to explain this.

This map is a very good, detailed map of central-northern Europe. Here south-east and eastern England are on par with much of the Netherlands and a bit less than old Anglian and Saxon areas, which makes sense if you combine Angles + Saxons + Danes + Frisians + Britons, and perhaps some other stragglers from other parts as well. Of course it's more important to know the types of R1a found in each area but this is still a good overview:

[sioned]

Modern Frisian which is today spoken is heavenly influenced with Standard Dutch language, which is a shame, because Frisian language losing its uniqueness by borrowing Dutch words. I assume the same trend is taken place with Frisian in Germany and Frisians in Denmark