Harlingerland Frisian is an extinct dialect of the East Frisian language.[2] It was known for giving several features originally in Old Frisian.[3] The language was only documented in the year 1691 with the book Memoriale linguae Frisicae, by Johann Cadovius-Müller.[4] This dialect then slowly vanished and was displaced by the Harlings dialect of Low German.[5] It belonged to the Weser dialects alongside the Wursten and Wangerooge Frisian dialects.