Read "Space Viking" by H. Beam Piper online for free on Textopian. Full text with search, annotations, highlights, and AI-powered reading aids.
Beowulf was bad.
Valkanhayn and Spasso had both been opposed to the raid. Nobody raided Beowulf; Beowulf was too tough. Beowulf had nuclear energy and nuclear weapons and contragravity and normal-space craft, they even had colonies on a couple of other planets of their system. They had everything but hyperdrive. Beowulf was a civilized planet, and you didn't raid civilized planets, not and get away with it.