Author
- John Gage1
- John Harington1
- John II of Castile1
- John XXI1
- John de Beauchesne1
- John of Ibelin1
- John of Lancaster, 1st Duke of Bedford1
- John Dokeianos1
- John, Duke of Berry1
- Joseph ben Moses Sarfati1
- Josephus1
- Juan Martínez Silíceo1
- Juan de Mena1
- Juan de Torquemada1
- Juana I of Castile1
- Julius III1
- Jullien Gervais1
- Justin1
- Kingdom of Bohemia1
- Kingdom of France1