. "Because she ate a pomegranate in the Underworld before she went up to Olympus to be with her mother. When she arrived at Olympus her mother asked if she ate anything while in the Underworld, knowing that if she had her daughter's soul would have to spend a third of the year in the Underworld. Then she was forced to marry Hades."@en . . "Why did Persephone have to stay in the underworld"@en . "Because she ate a pomegranate in the Underworld before she went up to Olympus to be with her mother. When she arrived at Olympus her mother asked if she ate anything while in the Underworld, knowing that if she had her daughter's soul would have to spend a third of the year in the Underworld. Then she was forced to marry Hades."@en .