Space Viking. by H. Beam Piper

Initially serialized in Analog magazine between 1962 and 1963, Space Viking takes place after the events of H. Beam Piper's earlier serialization, The Cosmic Computer. Space Viking is a classic space opera : what begins as an interstellar tale of revenge turns into a swashbuckling adventure yarn, and finally into a meditation on empire-building and galactic governance with direct allusions to our modern history.
This richness of content makes Space Viking a unique read. The reader begins by expecting a lighter sci-fi adventure, and early on the plot delivers ; but as events transpire, the reader is deftly drawn away from action scenes and into a more nuanced discussion on governance and human nature.