Recorded in a wide range of spellings including Trethewy, Thethewey and the anglicised forms of Tredry, Tredway, Treadway and Treadaway, this unusual surname is Cornish. It is a locational surname from any of the various places in Cornwall called Trethewy or Trethewey. The name means 'David's settlement', derived from the Cornish (Celtic) word 'tre', meaning homestead or settlement, and 'Dewi', an early Celtic form of the personal name 'David' which is still used in Wales along with the later Dafydd. The name 'David' means 'beloved', and was very popular in Wales, since that country's patron saint was St. David, and has continued to enjoy great popularity throughout the United Kingdom. Early examples of the surname recordings taken from surviving church registers of mainly Greater London include: Agnes Tredway, christened at Harlington in Middlesex, on February 2nd 1557, Elizabeth Trethewey, who was christened at Truro in Cornwall, on August 4th 1629, Ann Treadway, who was christened at St Ann's Blackfriars, on October 13th 1683, and Ann Treadaway, the daughter of Francis Treadaway, who was christened at St Martins in the Field, Westminster, on May 15th 1795. The first recorded spelling of the family name is shown to be that of Andrew de Tredewi. This was dated 1210, in the Feet of Fines court records of Cornwall, during the reign of King John of England, 1199 - 1216. Throughout the centuries, surnames in every country have continued to "develop" often leading to astonishing variants of the original spelling.