Aelius Donatus
In the 4th century, Aelius Donatus compiled the Latin grammar "Ars Grammatica" that was to be the defining school text through the Middle Ages. A smaller version, "Ars Minor", covered only the eight parts of speech; eventually when books came to be printed in the 15th century, this was one of the first books to be printed. Schoolboys subjected to all this education gave us the current meaning of "grammar" (attested in English since 1176).