The works of the enigmatic seventh-century author Virgilius Maro Grammaticus ('Virgil the Grammarian') are amongst the most puzzling medieval texts to survive. Ostensibly a pair of grammars, they swarm with hymns, riddles, imaginary writers, invented words and attacks on authority. Conventionally interpreted either as a benighted barbarian's unfortunate attempt to write a 'proper' grammar, or as a parody of the pedantic excesses of the ancient grammatical tradition, these texts are desperately in need of a reading which takes into account their many idiosyncrasies. Why should a grammarian preach the existence of twelve different kinds of Latin? Why should he attack the very notion of authority, thereby destabilising his own position? The search for an answer leads via patristic exegesis and medieval wisdom literature to the tantalisingly ill-documented reaches of heterodox initiatory traditions.