Federation

Space Viking is a science fiction novel written by H. Beam Piper and is set in his Terro-Human future history. It tells the story of one man's search for his wife's murderer and its unexpected consequences. Ten thousand refugees from the losing side of The Big War (The System States War of The Cosmic Computer) fled far beyond the boundaries of the Terran Federation and colonised the planet Excalibur. By the beginning of Space Viking, they had expanded to a handful of Sword Worlds (so-called because they are named after legendary swords) and had grown to a total population of three and a half billion, organised in a feudal system of kingdoms, duchies, and other small states, ruled by frequently warring noblemen. Despite their isolation and the political instability, the inhabitants managed to retain a high level of technology, including space flight. (Excerpt from Wikipedia)

Terra has a problem. The Ullr are uprising and the uprising must be put down at any cost. A brilliant retelling of the Sepoy Mutiny set against an interstellar empire. H. Beam Piper was one of the best writers of space opera that science fiction ever produced. Well written, insightful, and revealing.