The most famous myth about Persephone is the story of her abduction.
Hades, the ruler of the Underworld, decided that he wanted to marry Persephone, his sister Demeters's only daughter. One day, as she was gathering flowers in the Nysian meadow with her maidens, she wandered apart from the group ensnared by the sudden blooming of a glorious fragrant flower (some say it was a narcissus). As she reached to pluck it, the ground below her feet opened up and Hades, in his four-horse golden chariot, appeared before her in all his power and majesty. He snatched her and took her with him to the Underworld, to be his wife and queen.
Needless to say, Demeter wasn't very pleased when she found out from Hecate and Helios what had happened. Hurt and distraught, she started wandering aimlessly around and was aggrieved to such an extent that she neglected all her duties. And since she was the goddess of agriculture and fertility, the earth was now barren, and people were dying of famine.
Seeing no way out of it, Zeus (who some say must have approved Hades' abduction in the first place) sent Hermes to the Underworld to fetch Persephone back to her mother. The divine messenger did do precisely that, and Demeter and Persephone were once again reunited on Olympus.
However, either on her own accord or, more probably, after being tricked by Hades, Persephone had tasted one pomegranate seed before leaving the Underworld. This, according to the ancient laws, obliged her to remain in the Underworld.
Zeus proposed a compromise: Persephone would spend two-thirds of the year with her mother, and one-third with her new husband. Everybody agreed – and that's how the seasons were born and how the growth of crops was explained.
Just like a seed, Persephone spends few months of the year below the earth. This is the period of Demeters's grief which coincides with the dark, winter months. However, when the time comes for Persephone to go back to her mother, Demeter brings back the light and the warmth and the earth rejoices in abundance.