Ancient kingdom, not all in South Africa (6)
I believe the answer is:
sparta
'ancient kingdom' is the definition.
The answer and definition can be both locations as well as being singular nouns.
Perhaps they are linked in a way I don't understand?
'not all in south africa' is the wordplay.
'not all' becomes 'part' ('part' is the opposite to 'all').
'in' is an insertion indicator.
'south africa' becomes 'SA' (abbreviation).
'part' inserted into 'sa' is 'SPARTA'.
Can you help me to learn more?
(Other definitions for sparta that I've seen before include "Ancient Greek city synonymous with austerity" , "Ancient Greek city state" , "Ancient Greek city-state" , "Ancient Greek city known for warlike spirit" , "Ancient Greek city whose citizens were noted for hardiness" .)