He renamed the months of the year after himself

The ego of Commodus was unmatched. He genuinely thought of himself as a living deity. He even put pressure on the Senate to formally recognize him as a living god by having the head of the Colossus severed and replaced with his visage. But he wasn't just any deity; according to Commodus, he was the Greek hero Hercules. When his lunacy reached its peak, he began to wander around wearing a lion's skin cloak to make himself appear more like Hercules and insisted that everyone speak to him as "Hercules, son of Zeus."

Unsurpassable in his attempts to reestablish the whole Roman Empire was Commodus' ego. He began renaming items all across the Empire. It was merely a tactic to force people to give praise even when they didn't want to. First, Commodus refounded Rome and gave the city and its inhabitants the names Commodiana and "Commodianus." Then he gave the name "Colonia Lucia Annia" to Rome. Legions changed over this process to become Commodianae. "Alexandria Commoduiana Togata" was the new name of the fleet that transported the grains from Africa. Commodus gave his name to every month of the year by renaming them. For example, September was renamed "Heracles," while August was renamed "Commodus."