Murong De
In 400, Murong De claimed the title of emperor, and he changed his name from Murong De to Murong Beide (慕容備德) to allow his people easier obedience of naming taboo rules—and presumably, this meant that the people would only be in violation of the taboo on his name if they used "Beide" together, not "Bei" or "De" individually, as both were common characters. He created Princess Duan empress.