- Orso, Saint1
- Orthodox Eastern Church1
- Ospedale degli Innocenti (Florence, Italy)1
- Pamphlets1
- Papal documents1
- Papal legates1
- Parva naturalia (Aristotle)1
- Passion of Jesus Christ1
- Passover--Liturgy1
- Paul III, Pope, 1468-15491
- Paul V, Pope, 1552-16211
- Penitentials1
- Penmanship, Arabic1
- Persian letters1
- Persian prose literature1
- Pesciori, Guglielmo1
- Philip II, King of Spain, 1527-15981
- Philip III, King of Spain, 1578-16211
- Philip IV, King of Spain, 1605-16651
- Philosophy and religion1