Some writers in Classical times considered Theseus to have been a historical, rather than a mythological figure. It was even claimed that the episode in the Underworld actually took place in a real-world kingdom. Its ruler, named Pluto (another name for Hades), had a daughter named Persephone and a vicious Molossian hound named Cerberus. When the heroes tried to carry off Persephone, her father locked up Theseus and set the dog on Peirithous. Historical or not, Theseus was the national hero of Athens. He was said to have united all the feuding warlords of the Athenian countryside into a federation. He was renowned for his sense of justice and his defence of the oppressed. Escaped slaves taking refuge at his altar in historical times could not be taken back into bondage.