The Gatehouse website record of a licence to crenellate for Lincoln Bishops Palace granted on 1329 Sept 28

Licence for Henry, bishop of Lincoln and Chancellor, — in consideration of his profitable services and the great place he holds in the direction of the king's affairs, — and for his successors, bishops of Lincoln, to repair, raise, crenellate and turrellate the walls of his palace which adjoins the precinct of St. Mary's, Lincoln, now partly enclosed with a stone wall, crenellated and turrellated, and if necessary to make new walls in the circuit of the palace, and to crenellate and turrellate them as often as and as they think fit. Further grant to them, in frank almoin, of the old wall, and the soil on which it is situated, adjoining the palace towards the East, which wall contains 18 and a half perches per virgam viginti pedum de ulna regia, and the like licence to crenellate, etc., the same. Further grant that both the soil on which the wall is situated and the palace shall have the immunity and ecclesiastical liberty of the church, its cemetery and other places within the precincts, all offenders in the former to be held violators of the liberties of holy church just as if they had offended in the latter. By p.s. (CPR)

muros palatii sui in civitate Lincoln. quod quidam palatium se jungit procinctui dictae ecclesiae beatae Mariae Lincoln. qui quidem procinctus de licentita progenitorum nostrorum &c. clauditur et kernellatur, et diversi turelli ibidem facti sunt ut dicitur, reparare et emendare necnon altius undique elevare, kernellare et turellare, &c. et si opus fuerit alios muros in circuitu dicti palatii de petra et calce de novo facere kernellare et turellare, &c. Dedimus insuper, &c. veterem murum nostrum et solum in quo idem murus situatur qui se jungit palatio praedicto versus orientem qui quidem murus continet decem et octo perticatas et dimidiam per virgam viginti pedum de ulna regia ut dicitur, &c. murum illum emendare vel eum si opus fuerit de novo facere, kernellare et turellare, &c. (Turner and Parker)

Original source is;

Lyte, H.C. Maxwell (ed), 1891, Calendar of Patent Rolls (1327-30) p. 453-4 online copy

(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 sources are;

Thompson, M.W., 1998, Medieval bishops' houses in England and Wales (Aldershot: Ashgate Publishing) p. 167
Coulson, C., 1982, 'Hierarchism in Conventual Crenellation' Medieval Archaeology Vol. 26 p. 76-7, 93 online copy
Foster, C.W., 1931, 'Appendix I Episcopal Residence at Lincoln' Registrum Antiquissimum of Lincoln (Lincoln Record Society 27) Vol. 1 p. 267-76 esp. 275 online copy
Turner, T.H. and Parker, J.H., 1859, Some account of Domestic Architecture in England (Oxford) Vol. 3 part 2 p. 409 online copy

Burghersh, Henry (c.1290–1340)

Treasurer and Chancellor of England 1328-1330, 1334-37. Was a supported of Queen Isabella.

The 1329 licence was granted when Mortimer and Isabella were regents. (ODNB)

Biographical source include;

Nicholas Bennett, 2004, ‘Burghersh, Henry (c.1290–1340)’ Oxford Dictionary of National Biography (Oxford University Press) online copy (subscription may be needed)