No Welsh leader in wealthy English city (7)
I believe the answer is:
norwich
'english city' is the definition.
(I've seen this before)
'no welsh leader in wealthy' is the wordplay.
'leader' indicates taking the first letters.
'in' is an insertion indicator.
'wealthy' becomes 'rich' (similar in meaning).
The initial letter of 'welsh' is 'w'.
'w' placed into 'rich' is 'rwich'.
'no'+'rwich'='NORWICH'
(Other definitions for norwich that I've seen before include "Administrative centre of Norfolk" , "English city" , "E. Anglian county town" , "Juliana of - (Revelations of Divine Love)" , "County town of Norfolk" .)