This is a Cornish locational surname, although one not recorded in the book of Cornish surnames. It originates from a now "lost" hamlet called Carwithan or similar from the pre medival "ker-gwydh", and probably translating as the fort in the wood. This place may have been in the vicinity of the small village of Boyton, on the river Tamar, near Launceston, since it is from Boyton that most of the early church register recordings of the surname, are to be found. The surname appears in a number of spellings including Carwithan, Carwithen, Carwithim, Carwithon, and the "original" Karwethan. Some five thousand British surnames originate from lost places, although it is unusual to find examples from Cornwall, where the communities were generally more "fixed" than in other regions. Early examples of the surname taken from authentic church records for the county include Margerie Carwithan, christened at Boyton on September 23rd 1578, Frauncis Carwithim, the son of Persival Carwithim, born at Boyton on July 6th 1634, and Roger Carwithen, who married Anne Saunders at Stratton, on March 27th 1774. The first published recording of the surname may be that of Izal Karwethan, the son of George Karwethan, christened at Wendron, Cornwall, on May 2nd 1585. This was during the reign of Queen Elizabeth 1st, known as "Good Queen Bess", 1558 - 1603.