In 1305 Feb 2, Johannes de Segrave, senior (Stephen de Segrave) was granted, by Edward I, (In year 33 of his reign) a Royal licence to crenellate Calvedon (Caludon Castle)

"Licence for John de Segave the elder to crenellate his manor (manerium suum) of Calvedon, co. Warwick."

Granted at Walsingham, by privy seal.

At the end of C13 the Earl of Chester granted Caludon to Stephen de Segrave. He is believed to have been responsible for erecting the first house at the site and was granted a licence to crenallate it in 1305 [Parker writes Johannes de Segrave, senior].

Original source is

• Calendar of Patent Rolls (1301-7) p314

(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;

• Stephens, W.B., 1969, 'The City of Coventry: The outlying parts of Coventry: Wyken and Caludon', VCH Warwick Vol8 p121-2
  Turner, T.H. and Parker, J.H., 1859, Some account of Domestic Architecture in England (Oxford) Vol3 pt2 p405

More details about licences to crenellate can be found here.

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