Her daughter was abducted

Persephone, the daughter of Demeter, subsequently rose to power as the ruler of the underworld. When Persephone was having fun with her nymph friends, the underworld god Hades kidnapped her. Demeter was enraged at the episode, but she was unaware that her husband Zeus had authorized Hades to act in such a manner. Demeter started looking all over the world for her daughter but was unsuccessful. She had neglected to look after herself because she was so anxious to find her daughter. Hecate, the goddess of the Moon and witchcraft, contacted Demeter after observing her distress. She admitted to Demeter that she had heard Persephone's cries but had no knowledge of the kidnapper.

Knowing this, Demeter hurried to Helios (the Sun), who informed everyone that Zeus had authorized Hades to take Persephone forcibly to the underworld. Demeter was so furious after learning the truth that she decided to postpone going back to Mount Olympus until she had her daughter back. She started out residing among mortals on earth.