Prepare central King's territory maybe (6)

I believe the answer is:

domain

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'king's territory maybe' is the definition.
I can't judge whether this defines the answer.

'prepare central' is the wordplay.
'prepare' becomes 'do' (I've seen this in other clues).
'central' becomes 'main' (I've seen this in another clue).
'do'+'main'='DOMAIN'

Can you help me to learn more?

(Other definitions for domain that I've seen before include "Field of thought or activity" , "Special region, area of expertise" , "Sphere or territory" , "Range of influence or field of activity" , "Sphere of activity" .)

I've seen this clue in The Telegraph.

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