Rein in rebellion, imprisoning contrary artist (7)
I believe the answer is:
bernini
'artist' is the definition.
(I have seen 'Italian artist' mean 'bernini' so perhaps 'artist' could also mean 'bernini')
'rein in rebellion imprisoning contrary' is the wordplay.
'imprisoning' says the answer is hidden in the clue (the answer is imprisoned within the clue).
'contrary' is a reversal indicator.
'ininreb' is hidden within 'rein in rebellion'.
'ininreb' back-to-front is 'BERNINI'.
(Other definitions for bernini that I've seen before include "Giovanni -, seventeenth century Italian artist; bin Reni (anag.)" , "Italian sculptor of several landmarks of Rome" , "Italian artist and sculptor" , "Italian sculptor who worked in Rome" , "Italian seventeenth century sculptor, architect and painter" .)