The twenty-ninth day of June.
- 1849. Pope Pius IX appeals to Napoleon for military support.
- 1868. Pope Pius IX summons the First Vatican Council with the papal bull, Aeterni Patris.
- Saints Peter and Paul, i.e. the Apostles Peter and Paul of Tarsus; also a local holiday in Rome, of which they are patron saints, as well as of the diamond workers.