This interesting surname is of Anglo-Saxon origin, and is a locational name from one of the various places in England called Heydon and Haydon. Haydon in Dorset, recorded as "Heidon" in the 1201 Feet of Fines, in Somerset, recorded as "Haegdun" in the Early Saxon Chronicles (1046), and in Wiltshire recorded as "Haydon" in the 1242 Book of Fees, all derive from the Olde English pre 7th Century "Heg", hay (or perhaps "hege", hedge, or "(ge)haeg", enclosure) with "dun", down, hill, mountain; hence "hay down". eydon in Norfolk, recorded as "Heidon" in the 1196 Feet of Fines, derives from the same elements, but because of it's topographical position must be taken to mean "hay hill". Haydon in Cambridgeshire, recorded as "Haidena" in the Domesday of 1086, and Haydon Bridge in Northumberland, recorded as "Hayden" in the 1236 Book of Fees, have the Olde English "denu", valley, as their second element; hence "hay valley". In some instances the surname may be of Irish origin, and an Anglicized form of the Gaelic "O Eideain", descendant of Eidean, a personal name from a diminutive of "eideadh", clothes, armour. The surname can be found as Haydon, Heyden, Heydon and Heiden. Walter Haydon is listed in the Subsidy Rolls of Somerset (1327). Recordings of the surname from London Church Registers include; the marriage of Jane Hayden and Nycholas Asheton on October 28th 1552, at St. Michael's, Cornhill, and the christening of Thomas Hayden on July 6th 1570, at St. Andrew's, Halborn. The first recorded spelling of the family name is shown to be that of Thomas de Haiden which was dated 1200, in the "Place Names 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.