238th Pope of the Catholic Church. Pontificate 1667 - 1669. Clement IX worked to strengthen Venetian defences against the Turks on the island of Crete. Clement IX continued his interest in the arts. He embellished the city of Rome with famous works commissioned to Gian Lorenzo Bernini, including the angels of Ponte Sant'Angelo and the colonnade of Saint Peter's Basilica. He also opened the first public opera house in Rome.