This very unusual surname would seem to have been first recorded (see below) in the 17th century. As such it is a developed form of an earlier name. Either 'Enos' is of Olde English pre 7th century origins and a dialectal of 'Earn' meaning the 'eagle', or it is again dialectal, but of Olde French origins from the female 'Anes'. The latter was introduced by the Normans after 1066 and like Ann(e) is a development of Agnes, itself of Greek origins and meaning 'pure and chaste'. 'Earn' was a nickname for somebody of bold or courageous disposition, possibly a warrior or messenger, certainly a person of forceful character. The national sport of the medieval period seems to have been that of devising names which were often satirical, usually robust, and regularly obscene! It is not easy to explain why name spelling changes occur, except to say that only one in ten of the pre 19th century population could read, and local dialects were much more pronounced than now. It is said that William Shakespeare himself spelt his name in four different ways. In this case we have early examples of the recordings as follows - Elizabeth Eanis who married John Hooke at the church of St Christopher Le Stocks, London, on September 22nd 1588, and Ricardus Enos who married Maria Taylor at the famous church of St Martins in the Fields, Westminster, on November 24th 1630. This was possibly the first recording in the 'modern' spelling. Later examples are Mary Enos, daughter of Samuel and Elizabeth Enos, christened at St Sepulchre Church, London on May 6th 1740, and Charles James Enos, son of Charles and Honor Enos, christened at St James Church, Paddington, on July 4th 1832. The first recorded spelling of the family name is shown to be that of John Anneys, which was dated 1296, in the Charter Rolls of the County of Sussex, during the reign of King Edward 1, 1272 - 1307. 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.