Rape of Persephone
As Kore was picking flowers, Hades rose from the underworld and kidnapped Kore on his team. Kore, now referred to as Persephone, resigned herself to her fate. Her mother Demeter was now wandering around in despair and in her grief prevented all plants from growing, which forced Zeus to intervene because there was a danger that the entire world would perish from hunger. Eventually an agreement was reached that stipulated that Persephone would only stay in the underworld for part of the year, four months of the year. Accordingly, winter occurs when Kore reigns as Persephone in the underworld, and summer, the remaining 8 months, when Kore lives with her mother.