This is the story of RAMA and how he fought the ten-headed rakshasa king of Lanka, RAVANA. 

After a great penance, Raavana had received a boon from Brahma that he should be invulnerable and invincible against Devas, Asuras, Gandharvas and other divine beings. In his arrogance about his great strength, Ravana did not care to ask for security against mankind and other living beings on earth such as birds and animals. He became wicked and insolent; he began to ill-treat all and had become a real pest to the Devas and to the holy men because he knew none of them could defeat him - after all, he had the boon from Brahma himself..
    Utterly helpless, they came to the Great God, VISHNU, for help. VISHNU had a plan to help them.