Exili was an Italian chemist and poisoner in the 17th century. His real name was probably Nicolò Egidi. Few authentic details of his life exist. Tradition, however, credits him with having been originally the salaried poisoner at Rome of Olympia Maidalchina, the sister-in-law of Pope Innocent X. Subsequently, he became a gentleman in waiting to Queen Christina of Sweden, whose taste for chemistry may have influenced this appointment.