A shield wall formation was probably the most common formation before gunpowder was invented worldwide all throughout history. The legs of anyone facing a shield wall were especially vulnerable from the underhanded thrust. Strength lay in unity as a collective and shields could also be raised to deflect incoming arrows.
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.