In 1406 March 19, Thomas Wykeham, armiger was granted, by Henry IV, (In year 7 of his reign) a Royal licence to crenellate Broghton (Broughton Castle)

"quod Thimas Wykeham armiger possit kernellare manorium manerii sui de Broughton."

Granted at Westminster, by King.

Original source is

• Calendar of Patent Rolls (1405-8) p161

(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, 2006, Greater Medieval Houses Vol3 (Cambridge) p212
  King, D.J.C., 1983, Castellarium Anglicanum (London: Kraus) Vol2 p389n3
  Turner, T.H. and Parker, J.H., 1859, Some account of Domestic Architecture in England (Oxford) Vol3 pt2 p270, 421

More details about licences to crenellate can be found here.

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