In 1379 July 26, Johannes d' Arundell, miles (John Darundell; Sir John Fitzalan) was granted, by Richard II, (In year 3 of his reign) a Royal licence to crenellate Bechesworth (Betchworth Castle)

"Licence for the king's kinsman, John Darundell, knight, to crenellate his dwelling-house (mansum) of Bechesworth, co. Surrey, to enclose his wood of Herteswode, and to impark 360 acres of land adjacent thereto. "

Granted at Westminster, by privy seal.

also enclose his wood of Herteswode and impark 360 acres of adjacent land.

Original source is

• Calendar of Patent Rolls (1377-81) p380

(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) p440
  King, D.J.C., 1983, Castellarium Anglicanum (London: Kraus) Vol2 p467n15 [date 1377]
  Turner, T.H. and Parker, J.H., 1859, Some account of Domestic Architecture in England (Oxford) Vol3 pt2 p418

More details about licences to crenellate can be found here.

Please let me know if you see any errors, can add information or can otherwise help to improve this resource. Contact me