The voyages and sagas of the vikings are very interesting, but something I find to also be fascinating is the economic and cultural history that brought about the viking age and then several centuries later ended it. It does seem kind of sudden; there was a niche that suddenly caused vikings to travel everywhere, and then it was just over.

Maybe it was good weather [1] on the isles for once?

[1] https://en.wikipedia.org/wiki/Medieval_Warm_Period