Damnatio memoriae is a way of punishing someone, even after they have died, by making sure nobody remembers them or talks about them. It was used a lot in ancient times, and it was usually used to punish people who had done something really bad. For example, if a Roman emperor did something really horrible, then the Roman government could decide to do damnatio memoriae, which meant they would try to erase all evidence of the person ever existing – they would take down statues and paintings of the person, take their name off of official records, and try to stop people talking about them. Basically, it was like a way to make it seem like the bad person had never existed!