Recorded in a number of spellings including Chastney, Chastay, Chastey, Chasty, Chasaye, Cheyney, Chesne, Chesney, and probably others, this is a surname of Old French origin. Introduced into England and later Scotland by the Norman-French invaders after the famous Conquest of England in 1066, the derivation is from the words chesne or chesnai meaning the oak tree or oak grove, and ultimately from the early Latin (Roman) "casnetum". The name may be either locational or topographical in origin. As a locational name it originates from any of the places in France which were originally spelt as chesnai. These include Quesnay in Calvados and La Manche, Le Quesnay in Seine-Inferieure, or Quesnay-Guesnon also in Calvados. As a topographical name it denoted residence near a conspicuous oak tree, perhap one where the local village council and court would meet. In a few cases the surname may have been a nickname for a man with a "heart of oak". In Scotland the first known bearer of the name was William de Chesne, a charter witness in the year 1199, whilst Hugh de Cheisnei was a land owner in Oxfordshire, England in 1166. The early surviving church registers for the county of Devonshire show Alice Chastie as marrying Richard Mouncell at Black Torrington, on February 8th 1619, whilst in the city of London Walter Chastey was a christening witness at St Dunstans in the East, Stepney, on April 17th 1662. The first recorded spelling of the family name is shown to be that of Radulfus de Caisned. This was dated 1086, in the Domesday Book for the county of Sussex, during the reign of King William 1st, known to history as "The Conqueror", 1066 - 1087. Surnames became necessary when governments introduced personal taxation. In England this was sometimes known as Poll Tax. Throughout the centuries, surnames in every country have continued to "develop" often leading to astonishing variants of the original spelling.