In 1285 May 8, dean and chapter (at the instance of Oliver, bishop of Lincoln) was possibly granted, by Edward I, (In year 13 of his reign) a Royal licence to crenellate (Lincoln Cathedral Close)

"for their better safety from night attacks in passing from their houses to the said church, to enclose the precinct of the said church with a wall, 12 feet high, in suitable places, at Pottergate street and at the street leading from the high road of the bailey (ballii) to the Estegate with the two adjoining lanes on the north side: the said wall to be provided with sufficent gates with locks, to the custody of which they and their successors shall appoint one of their body to close them at dusk and open them again before sunrise."

Granted at Westminster,

There is insufficient evidence to be certain about this possible licence to crenellate.

The Dean and Chapter received licenses to crenellate the Cathedral. The first for a 12 foot wall (issued 1285 and repeated 1316) the second to raise the wall and add turrets (issued 1318). The licence makes no mention of crenellations and might not be properly be considered a licence to crenellate. Clearly the imposition on the citizens of Lincoln, and rights of the castle, was the reason for such a document.

Original source is

• Calendar of Patent Rolls (1281-92) p161

(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. Licentia is best translated as 'freedom to' not 'permission'.)

Significant later source are;

• Coulson, C., 1982, 'Hierarchism in Conventual Crenellation' Medieval Archaeology Vol26 p76 [but not in the appendix list of licences]

Sutton [Lexinton], Oliver (c.1219–1299), bishop of Lincoln, was born into a family of small landowners... Sutton was an excellent bishop—just, conscientious, and deeply devoted to his diocese, which he hardly ever left except when summoned to convocation or parliament.
The Dean at the time was, probably, Nicholas Heigham.

Biographical source include;

• Rosalind Hill, ‘Sutton , Oliver (c.1219–1299)’, Oxford Dictionary of National Biography, Oxford University Press, 2004 [http://www.oxforddnb.com/view/article/26801, accessed 28 March 2008]
  

More details about licences to crenellate can be found here.

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