Kingdom Under Fire is set in the fantasy land of Bersiah and covers the struggle between the forces of light (Humans, Dwarves, and Elves) and the forces of dark (Ogres, Orcs, Undead, and others.One hundred years before the events of the game, an epic war was waged between the two forces until finally a legendary group known as the Knights of Xok defeated the forces of dark and brought peace to the land of Bersiah.
Two factions, light and dark, are playable in the game, with each side having units fulfilling the typical roles of warrior, archer, flying unit and wizards – as well as more powerful individual hero characters. The campaigns are split into 13 missions of which 10 are battles and the other three being a dungeon crawl for a hero character.
Source: Wikipedia, "Kingdom Under Fire: A War of Heroes", available under the CC-BY-SA License.