Author
- Ibn Daqiq al-Eid1
- Ibn Jumay‘1
- Ibn Khalawayh1
- Ibn Taymiyyah1
- Ibn al-Farid1
- Ibn al-Khabbaz1
- Ibn al-Nafis1
- Ildibrandinus1
- Innocent IV1
- Isidore of Seville1
- Izz al-Din ibn 'Abd al-Salam1
- Jacobus de Voragine1
- Johannes de Sacrobosco1
- John Chrysostom1
- John de Breton1
- John de Seccheville1
- Justinian I1
- Khāṭirī, Aḥmad ibn Muḥammad1
- Leo Archpriest1
- Mahmud ibn Abd al-Rahman al-Isfahani1