"Sebben, crudele" (Though not deserving) is an aria from Antonio Caldara's 1710 opera La costanza in amor vince l'inganno (Faithfulness in love conquers treachery). Although the opera itself has been rarely performed in modern times, Sebben, crudele remains a popular concert aria. It has been recorded by Cecilia Bartoli, Beniamino Gigli and Janet Baker, amongst others.
References
Sebben, crudele Wikipedia(Text) CC BY-SA