Country one governed (4)
I believe the answer is:
iran
'country' is the definition.
(Iran is an example)
'one governed' is the wordplay.
'one' becomes 'i' (Roman numeral**).
'governed' becomes 'ran' (I've seen this in other clues).
'i'+'ran'='IRAN'
(Other definitions for iran that I've seen before include "Country that was Persia" , "It was known as Persia until 1935" , "Tehran is its capital" , "Previously known as Persia" , "Iraq's neighbour" .)