James IV occasionally besieged old city to get old coins (5)
I believe the answer is:
aurei
'coins' is the definition.
(Roman coins)
'james iv occasionally besieged old city to get old' is the wordplay.
I cannot really see how this works, but
'city' could be 'ur' (ancient Sumerian city state) and 'ur' is present in the answer.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for aurei that I've seen before include "ancient gold coins" , "Ancient money" .)