US city before being taken by British general (8)
I believe the answer is:
monterey
'us city' is the definition.
(city in California)
'before being taken by british general' is the wordplay.
'before' becomes 'ere' (poetic term for 'before').
'being taken by' means one lot of letters goes inside another.
'british general' becomes 'Monty' (nickname for Field Marshal Bernard Montgomery).
'ere' put into 'monty' is 'MONTEREY'.
(Other definitions for monterey that I've seen before include "and 20 Down: Cheese resembling Cheddar" , "Californian town" , "Californian fishing port" , "Capital of California under the Spanish" , "resort in California" .)