This unusual name is of Anglo-Saxon origin, and a locational surname deriving from any of various places named with the Olde English pre 7th Century elements "myrige", pleasant, agreeable, and "feld", pasture, open country. These places include Merryfield, in Devonshire and Cornwall, and Mirfield in West Yorkshire; the latter is recorded in the Domesday Book of 1086 as "Mirefelt", and in the 1246 Assize Court Rolls of the county as "Mirifeld". Locational surnames were acquired by the lord of the manor and local landowners, and especially by those former inhabitants who had moved to another area, usually in search of work, and used the name of their birthplace as a means of identification. The surname has a number of variant forms, ranging from Merryfield and Merrifield to Mirrefield, Mir(e)field and Merrefield. An early and distinguished bearer of the name was one John Mirfield (flourished 1393), an Augustinian canon of St. Bartholomew's, Smithfield, London, who was a noted writer on medicine. The marriage of Isaball Mirfield and Henery Purr was recorded at St. Margaret in the Close, Lincolnshire. An early Coat of Arms granted to a Mirfield family depicts on a silver shield two green lions passant guardant in pale. The first recorded spelling of the family name is shown to be that of John de Merefeld, which was dated 1273, in the "Hundred Rolls of Somerset", during the reign of King Edward 1, known as "The Hammer of the Scots", 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.