Author
- Jabir ibn Hayyan1
- Jacob Saphir1
- Jacques de Vitry1
- Jean de Roquetaillade1
- Jewish Community of Pitigliano, Italy1
- Jewish community of unidentified city, Italy1
- Johannes de Sacrobosco1
- John Chrysostom1
- John XXII1
- John de Breton1
- John de Seccheville1
- Lactantius1
- Leo Archpriest1
- Leo III1
- Lorenzo Gondi1
- Luigi de' Medici1
- Marcantonio Aldegati1
- Mariano da Firenze1
- Martial1
- Matthew of Vendôme1