François Haverschmidt, also written as HaverSchmidt (February 14, 1835 in Leeuwarden – January 19, 1894 in Schiedam), was a Dutch minister and writer, who wrote prose under his own name but remains best known for the poetry published under the pen name of Piet Paaltjens.
During his student days, he had some of his poetry published in student magazines under the pen name of Piet Paaltjens, around whom a playful but elaborate mystification was created as Haverschmidt kept his poetry separate from his “serious” prose and sermons, not unlike Nicolaas Beets.
He became a prime suspect for being the anonymous author of the Oera Linda Book , the inferred reason being a practical joke  (a parody of the Bible to lampoon fundamentalist Christians) . However, many of his contemporaries believed the book to be authentic. This would have prevented Haverschmidt and his collaborators (if they were indeed the authors of the supposedly millennia-old text) from unmasking their hoax, which consequently completely backfired.
Haverschmidt became progressively more depressed, especially after his wife’s death in 1891, and ultimately committed suicide in 1894.