Hard workers in a city sacked long ago (7)
I believe the answer is:
trojans
'hard workers' is the definition.
(I've seen this before)
'a city sacked long ago' is the wordplay.
I cannot quite understand how this works, but
'a' could be 'an' and 'an' is located in the answer.
This explanation may well be incorrect...
'in' acts as a link.
Can you help me to learn more?
(Other definitions for trojans that I've seen before include "Hard workers" , "People of Paris" , "Hard-working types" , "Citizens of ancient city in Asia Minor invaded by Wooden Horse" , "noted for hard work" .)