According to Ryszard Derdziński the Tolkien name is of Low Prussian origin and probably means "son/descendant of Tolk", with Tolk meaning interpreter or negotiator and originating as a nickname. A number of other theories on the meaning of the name have been proposed, including that it is derived from the village of Tolkynen in East Prussia. J. R. R. Tolkien suggested the name was derived from the German adjective "tollkühn", meaning foolhardy. Several people with the surname Tolkien or similar spelling, some of them members of the same family as J. R. R. Tolkien, live in northern Germany, but most of them are descendants of recent refugees from East Prussia who fled the Red Army invasion. J. R. R. Tolkien's own knowledge of the family history was limited to its 18th-century German origin, according to Derdziński in part because he was "early isolated from the family of his prematurely deceased father."