In 1310 July 16, Walterus de Maydenstan, vallettus Regis was granted, by Edward II, (In year 4 of his reign) a Royal licence to crenellate Maydenstan (Maidstone)

"mansum suum in villa de"

Granted at {Westminster}, by King.

Original source is

• Calendar of Patent Rolls (1307-13) p271

(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., 1995, 'Battlements and the Bourgeoisie: Municipal Status and the Apparatus of Urban Defence' in Church, Stephen (ed), Medieval Knighthood Vol. 5 (Boydell) p194n297
  Turner, T.H. and Parker, J.H., 1859, Some account of Domestic Architecture in England (Oxford) Vol3 pt2 p406

More details about licences to crenellate can be found here.

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