It was the dawn of a new age, either late 800's, maybe early 900's. When the Vikings landed on the banks of the river Elbe. The war leaders called up the horse tribes to their south, promising a great store of loot from the ladened longships and met them near the Anhalt forest.
And that is about as far as I am going to stretch this scenario into "reality."
Its 300 points of Saxons (Jutes, Frisian, Et. Al) verses Vikings
https://philonancients.blogspot.com/2025/04/saxons-go-aviking-denmark.html
enjoy