PHILOSTRATE is the name Arcita takes when he returns to Athens in disguise in The Knight's Tale. In Boccaccio's Il Teseida delle nozze d'Emilia (1339-1341), Arcita takes the name Penteo, Tes IV.12. Chaucer has borrowed the pseudonym for Arcita from the title of another Boccaccio poem, Il Filostrato (1333-1339), which means "conquered by love." [Arcita]
The name occurs three times, twice medially, KnT 1428, 1558, and once in final rhyming position, KnT 1728.