Reichenbach im Kandertal is first mentioned about 1320 as "Richenbach". During the Middle Ages, the village occupied a strategic location on the trade route into the Canton of Valais. Two castles, Mülenen Castle, with the Letzi Mülenen wall, and Aris ob Kien Castle, were built during the Middle Ages to guard the road. A third castle, Faltschen Castle, may also be medieval, but this is not definitively known. The village was part of the "Herrschaft" of Mülenen. In 1352, Bern acquired the Herrschaft and with it the village.