"BRETBY, or Bradby, is a hamlet, in the parish of Repton, about a mile and a half from that village. Bretby Castle, the seat of the Earl of Chesterfield, is here; the scenery around which is very beautiful. The population returns for Bretby include those for MELTON [Ed: a.k.a. Milton] hamlet, together amounting to 325 persons."
[Description from Pigot and Co's Commercial Directory for Derbyshire, 1835]
There is a more current description of Bretby at Derbyshire UK.