There is only one document which gives information concerning the ruined castle on Ruppertstein mountain. This legal document is one of the most interesting concerning the Pfälzer castles, as it was written as a foundation document before the castle’s construction.
On the 8 th January 1198 Count Heinrich I. of Zweibrücken transferred to the Benediktine monastery and its brothers at Hornbach an estate in Käshofen. This act was performed in the presence, and with the consent, of the Count’s wife Hedwig and all his heirs.
In return the Abbot Werner of Hornbach following the advice of his brothers, officers and two important citizens, gave Count Heinrich I. the two mountains of Gutenberg (Gutinberc) and Ruprechtsberg (Ruprehtisberc). It is probable that Heinrich I.’s background motivation for the exchange was right to build defences or castles on these mountains. It was stipulated that in the case of settlements surrounding the mountains, the residents were obliged to pay taxes on their fields and gardens to the monastery. In addition Count Heinrich obtained two lower summits between the mountains to construct fortifications under the agreement that he would respect the property of the monastery.
Both castles were constructed due to the terms of an exchange not a purchase. Soon afterwards the Count of Zweibrücken built the residential castle Lemberg on the mountain Gutenberg, whereas on Ruppertsberg he built a fortification. The original name of this fortification is lost in the mists of time, the name “Ruppertstein” refers simply to the cliff.
Other historical information is unknown, the suppositions that Ruppertstein has a similar history as Lemberg Castle are exactly that. The discovery of a stove tile from the 15 th century lets us assume that the castle was still used in the late Middle Ages. The most probable suppostion is that the castle was abandoned at the time of the transfer of the office Lemberg to Hanau-Lichtenberg in 1570. There is no indication of destruction during the Succession War of the Pfalz in 1689.