Goddess Nageshwari, an aspect of Devi Shakti, was a great devotee of Lord Shiva. She learnt all the shastras and vidyas from the Lord. She then went on to contemplate on Lord Vishnu as well. Having been married to the powerful sage Jaratkaru, she gave birth to a divine child, Aastika. In the meantime, a king named Janamejaya planned to conduct the Sarpa Yaga, a fire ritual where snakes would be offered as sacrifice. All the Nagas (members of the snake clan), the angels and the Gods got perturbed by his plan, but could do nothing to help the situation. Aastika went to the Yaga just as Janamejaya was about to start the rituals. Janamejaya got so impressed by this divine countenance that he promised to give the boy anything he asked for. Aastika asked him to stop the Yaga, thereby saving the Naga clan from mass destruction. Having fulfilled her divine mission, Nageshwari proceeded towards Manasa Sarovar and then settled down in Haridwar as Manasa Devi. The benevolent Manasa Devi bestows immense boons on her devotees and helps them tide over their adversities and cures them of all their ills as well.