- Inquisition4
- Intellectual life10
- Interdict (Canon law)1
- International relations5
- Investiture (Feudal law)1
- Iran12
- Iran--Dizfūl1
- Iran--Sabzevār (Khurāsān-i Raz̤avī)1
- Iran--Shīrāz2
- Iran--Zarqān (Fārs)1
- Iraq1
- Iraq--Baghdad1
- Ireland1
- Isabel, of Coimbra, Queen, consort of Afonso V, King of Portugal, 1432-14551
- Isabella I, Queen of Spain, 1451-15041
- Isfarāyīnī, Muḥammad ibn Muḥammad, d. 1285. Lubb al-albāb fī ʻilm al-iʻrāb3
- Isfarāyīnī, Muḥammad ibn Muḥammad, d. 1285. Lubāb al-iʻrāb2
- Ishrāqīyah2
- Ishārāt wa-al-tanbīhāt (Avicenna)1
- Islam5