In 1377 March 5, Warinus de Insula (Sir Warren de Lisle) was granted, by Edward III, (In year 51 of his reign) a Royal licence to crenellate Shirburn (Shirburn Castle)

"mansum"

Granted at Sheen, by King, on the information of John, king of Castile.

King's note reads "For the possiblity that it is older than this, see Mackenzie, quoting from a letter of Brunetto Latini, apparently dating from about 1258. The existing fabric certainly does not suggest a castle of this age, still less the 11th cty. date mentioned in the letter, which in any case appears to be a forgery.

Original source is

• Calendar of Patent Rolls (1374-77) p434

(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 p389n17
  Turner, T.H. and Parker, J.H., 1859, Some account of Domestic Architecture in England (Oxford) Vol3 pt2 p275, 418

More details about licences to crenellate can be found here.

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