- Hymns, Latin1
- Illumination of books and manuscripts, Flemish1
- Illumination of books and manuscripts, Gothic1
- Illumination of books and manuscripts, Italian1
- Indulgences1
- Initials1
- Inquisition1
- Italy--Florence1
- Italy--Siena1
- Jesus Christ1
- Leather bindings1
- Lectionaries1
- Manuscripts, Dutch1
- Mary, Blessed Virgin, Saint1
- Mary, Blessed Virgin, Saint, in the liturgy1
- Massachusetts--Northampton1
- Mensural notation1
- Missals (Service books)1
- Monastic and religious life1
- Monasticism and religious orders1