Aunt's tale about sovereign's territory (9)

I believe the answer is:

sultanate

I'm a little stuck... Click here to teach me more about this clue!

'sovereign's territory' is the definition.
'sultanate' can be an answer for 'territory' (sultanate is a kind of territory). I am unsure of the 'sovereign's' bit.

'aunt's tale about' is the wordplay.
'about' is an anagram indicator.
'aunts'+'tale'='auntstale'
'auntstale' is an anagram of 'SULTANATE'.

Can you help me to learn more?

(Other definitions for sultanate that I've seen before include "Turkey was" , "Muslim dominion" , "Brunei?" , "Country" .)

I've seen this clue in The Irish Times.

Want a hint initially instead of a full solution? Install my app