This is a Cornish and sometimes Welsh surname, of Olde English pre 7th century origins. Recorded in a wide range of spellings (see below), it is locational or topographical and derives from the elements "tre" meaning homestead or settlement plus "hern" - iron. In both Cornwall and Wales "iron" was found in ancient times in some quantity. The surname spellings include Treherne, Trehearne, Treharne, Trahearn and the dialectal Trayhorne. Early examples of the surname recording taken from authentic surviving church registers include: Marie Treherne christened on May 1st 1578, at the church of St. Mary Aldermary, city of London, Evan Trayhorne, whose first name suggests that he was Welsh, a witness at the famous church of St Dunstans in the East, Stepney, on March 29th 1649, and Edwina Boucher Treharne, the daughter of William Treharne, christened on December 19th 1669, at St. Martin in the Fields, Westminster. An interesting recording is that of John Trehearne, aged 33, who is recorded as "living in Virginia on February 23rd 1622. The first recorded spelling of the family name may be that of Balthasar Treherne, which was dated 1565, at St. Annes church, Blackfriars, city of London. This was during the reign of Queen Elizabeth 1st of England, 1558 - 1603. Throughout the centuries, surnames in every country have continued to "develop", often leading to astonishing variants of the original spelling.