Research Notes:
Dudding states, [1]
The village of Hartshill in Warwickshire, from which the de Hardreshull family derived their name, is a hamlet of Mancetter not far from the Leicestershire border. In Domesday Book it is called Ardreshill and with Ansley contained two hides.
Shortly after the Survey was made the King gave this parish and the adjoining one of Ansley to Hugh earl of Chester, whose nephew Ranulph gave Hartshill and Ansley to his kinsman, Hugh.
Hugh de Hardreshull settled down here, took the name of the place, "and built himself a fair manor-house, situate with very much advantage for defence, viz. at the utmost point of a ridge, that stretcheth itself between two deep and narrow vallies; and had the reputation of a castle, as the tradition is, there being some embattled walls yet standing to testify as much."
It probably was a castle, forming one of the corners of a strategic triangle, for some years later an agreement was made between Ranulph des Gernons, son of Ranulph I earl of Chester, and Robert le Bossu, earl of Leicester, that no castle should be built between Hinckley and Coventry or Hinckley and Hardreshull by either of them, and if any other person should build one they would assist each other in demolishing it.
[1] Reginald C. Dudding, History of the Manor and Parish of Saleby with Thoresthorpe in the County of Lincoln (Horncastle: W. K. Morton & Sons, 1922), 26, citing Dugdale's Warwickshire and Agreements at large, Leicester collections 1384, [HathiTrust].