Accordingly, the twins were reborn on earth as twin demons, Hiranyakasiipu and Hiranyaksha, who came from the womb first. Their first earthly parents were Kasyapa-Prajapati and his wife Diti. After Hiranyaksha was killed by Lord Vishnu in his Vamana (boar) avatara (incarnation), Hiranyakasipu did austerities (tapas) in order to increase his strength and get revenge. He was so good at ascetic disciplines that he earned boons from Brahma and immediately conquered the three worlds. He was crowned Triloka Chakravarty (emperor of the three lokas [worlds]). He prevented everyone from saying Vishnu’s name or even thinking about him. He instituted his own worship with the mantra Hiianyaya namah (salutation to Hiranya). However, his son, Prahlada became a devotee to Vishnu and chanted Narayanaya namah (salutation to Narayana, in other words, Lord Vishnu). Hiranyakasiipu was killed by the Narasimha incarnation of Vishnu (as man-lion).