- Lollards1
- Lord's Supper1
- Louis IX, King of France, 1214-12701
- Louis, Saint, Bishop of Toulouse, 1274-12971
- Ludwig IV, Holy Roman Emperor, 1282?-13471
- Manners and customs1
- Manuscripts, Armenian1
- Manuscripts, Judeo-Arabic1
- Manuscripts, Persian1
- Margaret, of Antioch, Saint1
- Marriage (Canon law)1
- Marriage customs and rites, Medieval1
- Marriage law1
- Materia medica1
- Materia medica, Vegetable1
- Medicine, Persian1
- Medicine--Formulae, receipts, prescriptions1
- Menorah1
- Mercenary troops1
- Meschiati, Giovanni1