This is a very Olde Norse-Viking locational name which derives from the pre 8th century A.D. and the early colonisation of Britain by the Scandinavian invaders. The derivation is from Flats-Byr, the name meaning 'the dweller' at the farm (now spelt 'by') on the low lying level ground (the flats) or being a former inhabitant of the villages of Flasby or Flaxby in Yorkshire. The name appears several times in the Rolls of Furness Abbey (Yorks) C. 1160 as Flatesbi and Flasceby. The first recorded spelling of the family name is shown to be that of Flatebi of Yorkshire which was dated 1086 The Domesday Book during the reign of King William the Conqueror 1066-1087 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.