This interesting and most unusual surname is of Old Welsh and Cornish origin, and is a locational name from places so called in Wales and Cornwall. The place in Wales is composed of the Welsh "tre(f)", meaning homestead, settlement, and the Welsh personal name "Arthen", the name of the Bear and River God, also given to the King of Ceredigion in the 9th Century. In Cornwall, places called Trevarthen are found in the parishes of St. Hilary and Newlyn East, and are named with the Cornish element "tre(v)", homestead, settlement, and a personal name "Arthien", equivalent to the Welsh "Arthen", as mentioned above. Early examples include the christening of Christopher, son of John Trevarthen, on January 5th 1562, at East Newlyn, Cornwall; and the marriage of Sandy Trevarthen and Johana Hoskinge, also at East Newlyn, on October 2nd 1580. A Coat of Arms, depicting "a red boar passant, gold armed, between three red mullets, on a silver shield", was granted to a Trevarthian family in Cornwall. The first recorded spelling of the family name is shown to be that of Margaret Trevarthen, which was dated September 10th 1559, marriage to Alexander Michel, at East Newlyn, in Cornwall, during the reign of Queen Elizabeth 1, known as "Good Queen Bess", 1558 - 1603. Surnames became necessary when governments introduced personal taxation. In England this was known as Poll Tax. Throughout the centuries, surnames in every country have continued to "develop" often leading to astonishing variants of the original spelling.