Twenty years after the Norman Conquest, in 1085AD, King William first authorised the preparation of a Domesday survey to establish the value of all the manors in his Kingdom, for the purpose of calculating federal dues.
Thatcham is described in the survey as having thirty-five virgates and twelve borders, with sufficient arable land for twenty-five ploughs. In addition there were two mills, one hundred and forty seven acres of meadow (pasture) and a wood giving pannage for sixty pigs. There was a church and two clergymen, and twelve hagae (the houses or closes of townsmen). The total value of the manor was assessed at £34 per annum, a very considerable sum in those days. For comparison, the annual value of other manors were assessed as follows:
- Greenham £6
- Midgham £6
- Crookham £1
- Colthrop 10 shillings
