Author
- John Mandeville1
- John of Glastonbury1
- John of Lancaster, 1st Duke of Bedford1
- John, Duke of Berry1
- Joseph Angelet1
- Joseph ben Abraham Gikatilla1
- Josephus1
- Juan de Torquemada1
- Juana I of Castile1
- Kalonymus ben Kalonymus1
- Kamal al-Din ibn al-Humam1
- Khvājah Muḥammad Pārsā1
- Kingdom of Naples1
- Klaus von Stille1
- Konrad III. von Soltau1
- Leonardo Bruni1
- Lope de Espejo1
- Lorenzo Guglielmo Traversagni1
- Lorenzo de' Medici1
- Louis XII of France1