- Hugh, of Cluny, Saint, 1024-11091
- Hugh, of Lincoln, Saint, 1140-12001
- Hungary1
- Hunting1
- Hunting customs1
- Iceland1
- Illegible markings1
- Illumination of books and manuscripts, Carolingian1
- Illumination of books and manuscripts, Dutch1
- Illumination of books and manuscripts, English1
- Immortality1
- Immortality--Christianity1
- India--Goa (State)1
- Indulgences1
- Inner Light1
- Innocent III, Pope, 1160 or 1161-12161
- Innocent V, Pope, approximately 1224-12761
- Inquisition1
- Insular scripts1
- International relations1