Novel about British deposing leader in holy city (7)
I believe the answer is:
rebecca
'novel' is the definition.
(Daphne du Maurier novel)
'about british deposing leader in holy city' is the wordplay.
'about' becomes 're' ('re' means regarding or about).
'british' becomes 'b' (abbreviation e.g. in 'BBC').
'deposing leader in' means to remove the first letter.
'holy city' becomes 'mecca' (Islamic holy city).
'mecca' with its initial letter taken away is 'ecca'.
're'+'b'+'ecca'='REBECCA'
(Other definitions for rebecca that I've seen before include "Maxim she betrayed" , "Mrs de Winter (novel by D. Du Maurier)" , "Daphne du Maurier novel; girl's name" , "riotous girl" , "Isaac's wife" .)