WI the Vikings are blocked from Europe?

[Analytical Engine]

Yeah, more or less. Also, I feel you are unaware of whole Polabian Slavs thingy. I see no reason why Norse could not conquer and partly assimilate, partly exterminate them, instead of Germans. Also Nrthern Belarus (Polotsk and all that jazz) can be Danelawed, so to speak. Longboats can sail far up Dvina and tributaries, you know.

I am aware of the Polabian Slavs... Its just that a stronger uber-Frankish Empire would want to take it too...

 

[CanadianGoose]

What happens to this empire when the mongols come?

What "empire" are you talking about? Baltic and surroundings? It was virtually untouched by Mongols IOTL (their only northern foray stopped well south of OTL Novgorod and their Polish "trip" was through Southern Poland, well south of what Norse could control in region). Everything conquered by Mongols IOTL will be theirs ITTL, would Norse, Slavic or ASB dukes rule the Southern Russia and Central Europe. Well, ASB ones could use lightsabers, but everybody else will fall.

I am aware of the Polabian Slavs... Its just that a stronger uber-Frankish Empire would want to take it too...

May be yes, may be no. It seems to me that desire to secure borders from Slavic attacks was the reason for initial Frankish push. Seeing Veleti and Norse killing one another over control of cold sea and dense forest can convince Frankish kings to let those savages kill each over unopposed for some time. And then it could be too late. Norse will control the territory too firm for Frankish rulers to pick on them. I'm drawing Norsewank scenario, of course, but sometimes Clio gives us examples of such a wank.