London was given a grant of murage dated 18/9/1386.
This was in the form of:-
Wording
Grant of murage for ten years to the mayor, aldermen and citizens of London for repair of its walls and dykes. By p.s.
Granted by Richard II. (Regnal year 10). Granted at Westminster. Granted by p.s..
Details of the petition which resulted in this grant can be seen
at this link. 
Primary Sources
Maxwell Lyte, H.C. (ed), 1900,
Calendar of Patent Rolls Richard II (1385-89) Vol. 3 p. 210
online copy
Secondary Sources
Coulson, Charles, 2009, Murage Grants (Handwritten list and notes)
Record created by Philip Davis. This record created 18/01/2009. Last updated on 03/05/2012. First published online 5/01/2013.
