This early surname has both English and Irish origins. Its numerous spelling forms include Haydon, Heydon, Heyden, Heiden, Hedon, Hayden, and Haydn as examples. The original English surname derives from one of the villages such as "Haydon" in Dorset, recorded as "Heidon" in the Feet of Fines of Dorset in 1201, or perhaps Haydon in Somerset, recorded as "Haegdun" in the charter known as "Codex Diplomaticus aevi Saxonici" of 1046. The placename is composed of the initial element "heg", the Old English word for "hay", plus the second element which maybe either "denu", a small valley or possibly "dun", a hill. In Ireland where the surname is quite popular, it may be an anglicized version of the gaelic "O'hEideain", meaning "The descendant of Eidean", from the word "eideadh", translating as clothes or armour. The clan was originally centred on County Carlow, but is also confused with a Wexford family of Norman-English origins. Early recording examples include Richard de Haydon in the Hundred Rolls of York for 1273, and William de Heydon of Gloucester in 1301. Other examples are those of Walter Haydon in the Subsidy Rolls of Somerset in 1327, and Richard Hayden, of Foster Lane, London, in 1595. Martha Haydon was christened at St Giles Cripplegate, London, on October 31st 1675, and Martha Haydn, christened at St Clement Danes, Westminster, on February 15th 1841. The coat of arms was granted in Devon in 1620. It has the blazon of a silver field, three bars gemel in blue, on a red chief a fesse dancette in gold. The crest is a silver lion. The first recorded spelling of the family name is shown to be that of Thomas de Haiden, which was dated 1200, in the rolls of the county of Essex, during the reign of King John, known as "Lackland", 1199 - 1216. 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.