Story about returning nobleman (7)
I believe the answer is:
account
'story' is the definition.
('account' can be a synonym of 'story')
'about returning nobleman' is the wordplay.
'about' becomes 'ca' (abbreviation for 'circa'**).
'returning' says the letters should be written backwards.
'nobleman' becomes 'count' (count is a kind of nobleman).
'ca' reversed gives 'ac'.
'ac'+'count'='ACCOUNT'
(Other definitions for account that I've seen before include "books" , "credit arrangement" , "Narrative or invoice" , "Explanation of conduct" , "Bill; description" .)