"to enclose the churchyard of the cathedral church of Wells and the precinct of the canons' houses in the city with a stone wall, and to crenellate the same for their better security, making sufficient gates and posterns, to be opened at dawn."
Granted at Woodstock,
Clearly a defence against thieves rather than military although the actual buildings are more a status symbol than anything else. However, note should be made of Coulson's general comments on the general use of gates and precinct walls to symbolically represent social order and control.
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.
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