The third game in the Gensou Suikoden series. It takes place 18 years after the first game, and is set just west of Gensou Suikoden II's Dunan region. The game revolves around a war between the Grassland tribes and the Zexen Confederacy, with later interference by Holy Kingdom of Harmonia, the sole superpower in the Gensou Suikoden world. Gensou Suikoden III is unique in the series in that it follows three different main characters: Hugo (son of one of the Grassland tribal chiefs), Chris Lightfellow (Captain of the Zexen Knights), and Geddoe (a mercenary initially working for Harmonia). The True Fire Rune is also central to the story, and while the player gets to decide which of the main characters becomes its host, canonically it goes to Hugo, with Chris getting her father's True Water Rune and Geddoe keeping the True Lightning Rune which he already possessed.
This tag implicates gensou_suikoden (learn more).