In 1351 May 24, Marmaducus Conestable (Marmaduck, Constable of Holderness) was granted, by Edward III, (In year 25 of his reign) a Royal licence to crenellate Flaynburgh (Danish Tower, Flamborough)

"quandam cameram suam infra manerium suum de quod supra costeram maris situatur"

Granted at Westminster, by King.

Licensed in 1351 and 1352

Original source is

• Calendar of Patent Rolls (1350-54) p75

(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 p537n29
  Turner, T.H. and Parker, J.H., 1859, Some account of Domestic Architecture in England (Oxford) Vol3 pt2 p415

More details about licences to crenellate can be found here.

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