In Viking era Scandinavia the system designed for a peaceful transfer of power you don't always get it. The problem with the Scandinavian system is that when these people die their posse just dissolves doesn't get transferred to their kid and so everything starts over. There's a trickle-down economic effect here that plays into the whole dynamic for why this society can get very unstable.
This show picks up where Dan's Thor's Angels show left off. In the early Middle Ages Pagan Germanic-language speakers like the Vikings are a dying breed. Many of their contemporaries wish they'd die faster.