Author
- Otto III1
- Paschasius Radbertus1
- Patrick Graham, 1st Lord Graham1
- Pedro de Serra1
- Peter Cantor1
- Peter Olivi1
- Pius II1
- Plato1
- Polo, Marco, 1254-1323?1
- Pope1
- Pseudo-Bede1
- Pseudo-Joachim of Fiore1
- Publius Papinius Statius1
- Quintus Aurelius Symmachus1
- Rabanus Maurus1
- Ranieri Farnese1
- Ranulf Higden1
- Raymond of Penyafort1
- Remigius of Auxerre1
- Ricardus, de Mediavilla, approximately 1249-1308?1