Forst is the midpoint of the Forster Kirchspiel (parish), which was already a parochial and jurisdictional entity by the Middle Ages.

The landholders about 1790 were Saint Castor's Foundation (Stift St. Kastor) in Karden, the Barons of Clodt, the Counts of Leyen, the Counts Waldbott von Bassenheim, the Rosenthal Monastery and the Franciscan convent in Karden.

Vorne in Silber ein stilisierter schwarzer Tempel, hinten in Grün eine silberne Kirche, unten in Gold über drei roten Rauten vier rote Kugeln, jeweils balkenweise.

The temple on the dexter (armsbearer's right, viewer's left) side refers to the Roman settlement whose remnants were found in the cadastral area known as Stockborn.

The parish had nine estates and its midpoint was the old church, seen on the sinister (armsbearer's left, viewer's right) side, which in 1288 was named in Rudolf von Polch's will.