In 1469 May 2, Sir Thomas Pilkington was granted, by Edward IV, a Lancaster licence to crenellate Bury (Bury Castle, Lancashire)

"build to make and to construct walls and turrets with stone, lime and sand around and below his manor house in Bury in the County of Lancaster, and to shut in the manor house with such manner of walls and turrets; also to embattle, crenellate and machiolate those towers......'"

Original source is

• 1875, Report of the Deputy Keeper Public Records Vol37 pt. 1 'Charters of the Duchy of Lancaster' p179, No. 42

(In fact, the original source given is usually a transcription/translation of what are precious medieval documents not readily availably. It should be noted that these transcription/translations often date to the nineteenth or early twentieth centuries and that unwitting bias of transcribers may affect the translation. Care should also be taken to avoid giving modern meaning to the medieval use of certain stock words and terms.)

Significant later source are;

• Emery, Anthony, 1996, Greater Medieval Houses Vol1 (Cambridge) p263
  King, D.J.C., 1983, Castellarium Anglicanum (London: Kraus) Vol1 p251n30
  Farrer, William and Brownbill, J., 1911, VCH Lancaster Vol5 p131

More details about licences to crenellate can be found here.

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