The beginnings of Partenstein go back to at least the Middle Ages. The Burg Bartenstein (castle) was built around 1180 by the Counts of Rieneck for hunting and to protect the Wiesener Strasse connecting the village of Langenprozelten on the river Main to the valley of the Kinzig. The Rienecks had vast landholdings, and, during the 13th century, began an expansionist policy. From their main seat of Rieneck, in the east of the Spessart, they expanded, building castles to settle and incorporate additional land.