Legends around Dussehra
As per Hindu mythology, a demon by the name of Mahishasur was honored a boon of immortality by Lord Shiva. As per the boon, Mahishasur could not be killed or wounded by any weapon. Because of this power, he became a terror for the people on Earth and started to cause destruction.
To end the destruction, Durga was born. She was created by Lord Brahma, Vishnu, and shiva who gave their powers to create Shakti the divine feminine form of power and strength. Goddess Durga fought with the demon Mahishasura for nine days and on the tenth day she beheaded the demon.
As per another legend, Lord Rama worshipped all the nine forms of Goddess Durga on nine consecutive nights before he killed Ravana. Since then all divine incarnations of the goddess are worshipped on all nine days of the festival.