In 1377 Nov 7, Abbas et Conventus Abbatiae Scoe. Werburgae [Sancte Warburgae] was granted, by Richard II, (In year 1 of his reign) a Confirmation licence to crenellate Abbatiae Scoe. Werburgae [Sancte Warburgae] (Abbey of St Werburgh)

"Inspeximus and confirmation of letters patent, dated 28 March, 51 Edward III., being a licence for the abbot and convent of St. Werburg's, Chester, to enclose and crenellate that abbey and church (abbatiam)."

Granted at Westminster, by For half a mark paid in the hanaper.

The abbey paid half a mark for a confirmation of the licence 8 months after the original grant, after Edward's death.

Original source is

• Calendar of Patent Rolls (1377-81) p56

(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;

• Coulson, C., 1982, 'Hierarchism in Conventual Crenellation' Medieval Archaeology Vol26 p95
  Turner, T.H. and Parker, J.H., 1859, Some account of Domestic Architecture in England (Oxford) Vol3 pt2 p218, 417

More details about licences to crenellate can be found here.

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