"Mandate to make letters to Robert ... that he may crenellate his castles of Brouham and Pendragon, C. Westmoreland."
Granted at Langley,
The enrollment, the the Chancery Warrents, is mutilated.
Original source is
(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;
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