Simplify the following text for a Grade 9 native English-speaking person.
Original: I puritani is an Italian opera in three acts by Vincenzo Bellini , first performed in Paris , on January 25 , 1835 , libretto by Carlo Pepoli , after Jacques Ancelot and Xavier Boniface Saintine 's TÃ tes Rondes et Cavaliers , itself based on Sir Walter Scott 's Old Morality .
Simplified: It is his last opera . Its libretto is by Count Carlo Pepoli based on TÃ tes rondes et Cavaliers by Jacques-Fran Ã ois Ancelot and Joseph Xavier Saintine , which is in turn based on Walter Scott 's novel Old Mortality .