In 1344 Jan 28, Randulphus de Hastyngs (Ralph Hastings) was granted, by Edward III, (In year 18 of his reign) a Royal licence to crenellate Slyngesby (Slingsby Castle)

"Licence for Ralph de Hastynges to crenellate his dwelling-place (mansum) of Slyngesby, co. York. Licence also for him to impark a place called le Orchard of Slyngesby, in Slyngesby, and his woods of Slyngesby Frith, Colton and Surkilwode, with the lawn there."

Granted at Westminster, by privy seal.

Licence to crenellate granted to Ralph Hastings in 1344 and to William, Lord Hastings in 1474.

Original source is

• Calendar of Patent Rolls (1343-45) p190

(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) p421
  King, D.J.C., 1983, Castellarium Anglicanum (London: Kraus) Vol2 p539n92
  Turner, T.H. and Parker, J.H., 1859, Some account of Domestic Architecture in England (Oxford) Vol3 pt2 p414

More details about licences to crenellate can be found here.

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