In 1673, Johann Conrad Dippel was born in the castle, where he was later engaged as a professional alchemist. It is suggested that Dippel influenced Mary Shelley’s fantasy when she wrote her Frankenstein novel, though there is no mention of the castle in Shelley’s journals from the time. However, it is known that in 1814, prior to writing the famous novel, Shelley took a journey on the river Rhine. She spent a few hours in the town of Gernsheim, which is located about ten miles away from the castle. Several nonfiction books on the life of Mary Shelley claim Dippel as a possible influence.
There are rumors that during his stay at Frankenstein Castle, Dippel practiced not only alchemy but also anatomy and may have performed experiments on dead bodies that he exhumed. There are rumors that he dug up bodies and performed medical experiments on them at the castle and that a local cleric would have warned his parish that Dippel had created a monster that was brought to life.
There are local people who still claim today that this actually happened and that this tale was related to Shelley’s stepmother by the Brothers Grimm, the German ethnologists. However, none of these claims have been proven to this date, and some local researchers doubt any connection between Mary Shelley and Frankenstein Castle.