Persephone was the Queen of the Underworld
Persephone was the daughter of Zeus and the Greek goddess of vegetation, Demeter. Often she was defined as "Core", meaning the "maid".
One sunny day, while Persephone was picking flowers for her mother on the Nysian plain, Hades, the god of the Underworld, noticed her and fell strongly in love with her, so he decided to abduct her to the Underworld.
When Demeter realized the loss of her daughter, for nine days and nights she was wandering around in disguise searching for Persephone. When she finally met Helios, the god of the sun, he revealed Demeter all the truth about what had happened. Demeter got so furious that she wanted to have nothing more do with the Gods and left the Olymp and stopped all fertility on earth.
In order to put an end to the world's misery, Zeus decided it would be best to bring Persephone back to her mother. So he sent his herald Hermes down to the Underworld in order to fetch Persephone.
Hades could do nothing else but to obey to his master’s order. However, before releasing Persephone, he gave her seven seeds of pomegranate to eat. This way, Persephone would forever be connected to the Underworld and would stay there for four months every year.
This way, the seasons were created in the upper world. All the time Persephone was with Demeter, Demeter was so delighted, that the sun was shining and everything flowered. All the remaining time where Persephone returned to the Underworld, Persephone was in grief and nothing grew- it was the time winter set off in the world.