In 1338 July 16, Willielmus Heyron (Sir William Heron) was granted, by Edward III, (In year 12 of his reign) a Royal licence to crenellate Ford (Ford Castle, Northumberland)

"mansum suum apud manerium suum de Ford
Teste Edwardo duce Cornubiae et Cestriae filio nostro carissimo custode Angliae, apud Gippewicum xvj die Jul. per ispum Regem"

Granted at Ipswich, by King.

Parker footnotes "Refered to again 36 Edward III. Quod Willms Heron in feodo tenet manerium suum de Forde in Northumb. kernellatum per nomen castri sui, &c.
Coulson footnotes "For William Heron, lord of the strong fortress of Ford, crenellation alone was not enough (for the expression of lordly status). In 1340 he recieved express licence to call it a castle and gained extensive hunting rights nearby. Defence here was very necessary but status was no less important."

Original source is

• Calendar of Patent Rolls (1338-40) p114

(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) p159
  King, D.J.C., 1983, Castellarium Anglicanum (London: Kraus) Vol2 p368n127
  Coulson, C., 1979, 'Structural Symbolism in Medieval Castle Architecture' Journal of the British Archaeological Association Vol132 p85n45
  Bates, C.J., 1891, Border Holds of Northumberland (London and Newcastle: Andrew Reid) p9
  Turner, T.H. and Parker, J.H., 1859, Some account of Domestic Architecture in England (Oxford) Vol3 pt2 p412

More details about licences to crenellate can be found here.

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