I recall seeing IIII in my Cicero class and expressing confusion, but being informed by the professor that said style was more common historically. The Wikiped

I recall seeing IIII in my Cicero class and expressing confusion, but being informed by the professor that said style was more common historically. The Wikipedia citation for 9 is Commentarii de bello Gallico (Julius Caesar's Commentaries on the Gallic War), which interestingly comes from around the same timeframe (first century BC, toward the end of the Roman Republic).