Crossword Genius

Stalwart Tory earl shunned by Camilla and her old man, mistakenly (6,9)

Ross

I believe the answer is:

harold macmillan

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

Here is my best explanation:

'mistakenly' is the definition.
I know nothing about this answer so I cannot tell whether it can be defined by this definition.

'stalwart tory earl shunned by camilla and her old man' is the wordplay.
I cannot quite see how this works, but
'tory' could be 'r' (abbreviation for right) and 'r' is found within the answer.
an anagram of 'camilla' is 'acmilla' which is present in the answer.
'and' could be 'n' (common abbreviation for 'and') and 'n' is present in the answer.
'old' could be 'o' (common abbreviation eg in OE for Old English) and 'o' is found within the answer.
'man' could be 'hal' (I've seen this before) and 'hal' is located in the remaining letters.
This may be the basis of clue (or it may be nonsense).

Can you help me to learn more?

This clue was last seen in The Guardian