Stay calm, unlike Anne Boleyn (4,4,4)
I believe the answer is:
keep ones head
'calm unlike anne boleyn' is the definition.
I know nothing about this answer so I cannot judge whether this works.
'stay' is the wordplay.
I cannot really understand how this works, but
'stay' could be 'keep' (keeping is a kind of staying) and 'keep' is found within the answer.
This explanation may well be incorrect...
Can you help me to learn more?
(Another definition for keep ones head that I've seen is " Remain calm and in control".)