When Daityaraj Bali'sarmy of asuras and daityas was defeated by the gods in battle, he went to Sage Shukracharya to seek a way for recovering his lost power and kingdom.
Shukracharya advised him, ?You must perform the Mahabhisheka Vishwajeet Yajna and your power and strength will return to fight the next battle with the gods.?
Daityaraj made arrangements for the yajna and received a chariot, a quiver, a flag post and armour from the burning fire and incense. Days later, he launched an attack on Lord Indra and won the battle with Lord Indra fleeing from the field.
At his defeat, Indra could not sit idly or peacefully, so he went to Vishnu for help. At the same time Indra'smother Aditi, seeing her son in trouble, also approached Vishnu. How could Lord Vishnu turn down Aditi'srequest? So he said, ?Devima, do no worry. In the near future I will take birth as your son and will destroy Daityaraj.?
As time passed, Aditi gave birth to a boy who was named Vaman. On becoming a youth, Vaman decided to confront Daityaraj. Disguising himself as a Brahmin, he went to Daityaraj'shouse, where the latter and Shukracharya were performing a yajna. On seeing the Brahmin boy, Daityaraj welcomed him and asked him what he would like to get in alms. Vaman replied, ?I do not want food or clothes. All I want is some land to live and till. Promise to give me whatever land I am able to cover under my three steps that I take and I will bless you and leave.? Daityaraj willingly promised as he possessed ample land to gift away for a good cause.
Meanwhile the Brahmin boy began to grow taller and taller till he became larger than Earth itself. He took one and step claimed the whole Earth. On his second step he took Amravati. Now the sage, Shukracharya, become suspicious and turned to Daityaraj to warn, ?Don'tallow him to take the third step. I am positive he is no ordinary person.?
But how could Daityaraj go back on his words? So he allowed the Brahmin to take the third step.
The Brahmin asked, ?Now where shall I place my third step??
Daityaraj said to the Brahmin, ?You can place your third step on my head.?
Seeing how honest Daityaraj was, Lord Vishnu returned to his original form and blessed Daityaraj, ?I am pleased at your forthrightness and upright behaviour. From now on, you shall rule over pataal lok forever.?
Thus Daityaraj became the ruler of pataal lok, hell, and the gods continued to rule over Amravati, heaven.