Ruler's son changed the initial archives (9)

I believe the answer is:

tsarevich

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'ruler's son' is the definition.
I know nothing about this answer so I cannot tell whether this works.

'changed the initial archives' is the wordplay.
'changed' indicates an anagram.
'initial' suggests taking the first letters.
The first letter of 'the' is 't'.
't'+'archives'='tarchives'
'tarchives' with letters rearranged gives 'TSAREVICH'.

Can you help me to learn more?

(Another definition for tsarevich that I've seen is " Russian emperor's son; I've starch (anag.)".)

I've seen this clue in the Sydney Morning Herald.

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