Aelius Donatus

Aelius Donatus was a Roman grammarian and teacher of rhetoric who flourished in the middle of the fourth century AD. He wrote two grammatical works that dominated the teaching of Latin for over a thousand years: the Ars maior, a comprehensive treatise on Latin grammar, and the Ars minor, a guide to the parts of speech. The Ars minor in particular has been described as the leading grammar textbook and by far the most commonly used grammar between 400 and 1500 AD, remaining in wide circulation among educators throughout the Middle Ages and beyond, and its use only grew after the invention of the printing press. Donatus also pioneered an early punctuation system using dots placed at different heights to mark pauses of different lengths, a forerunner of the modern comma, colon and period.