For non-Earth planets, there is the Pythagorean Counter-Earth of John Norman's "Gor" series. For future SF, there is Bedesem Colony in "The Thrall" in Angela Knight's collection "Mercenaries". For alternate history, there is S. M. Stirling's "The Domination of the Draka." (Individual novels, "Marching Through Georgia", "Unde the Yoke", "the Stone Dogs" and "Drakon".)