- Jerónima de la Asunción, madre, 1555-16301
- Jewish law1
- Jews--Legal status, laws, etc.1
- Job (Biblical figure)1
- John IV, King of Portugal, 1604-16561
- John Manuel, Prince of Portugal, 1537-15541
- John V, King of Portugal, 1689-17501
- John VIII Palaeologus, Emperor of the East, 1392-14481
- John the Baptist's Day1
- Juana, of Austria, Princess of Portugal, 1535-15731
- Judaism (Christian theology)1
- Judaism--Liturgy1
- Judas Iscariot1
- Judges1
- Judgment of God1
- Julian, of Eclanum, Bishop, 380-approximately 4551
- Julius III, Pope, 1487-15551
- Justinian I, Emperor of the East, 483?-5651
- Kapitalbünde1
- Kings and rulers--Succession1