Vamana means dwarf in sanskrit, Lord Maha Vishnu took the avatar of a dwarf brahmin boy to save the world yet again from the asuras. Lets know the story of King Bali and Vamana.
King Bali was grandson of Prahalada whom Lord Vishnu has saved from his father Hiranyakashyapa in the avatar of Narasimha.
King Bali was learned and good king, he ruled so well that all the people on earth were most happy under his rule. though he was a asura he ruled following dharma.
Bali prayed to Lord Brahma to get a boon to become a good king and show the world that asuras can also be good along with that he also took a boon of remaining undefeated in any battle against any opponent.
Because Bali was a righteous king Lord Brahma blessed him with the boon.
Bali after that started expanding his empire and defeated Indra and took control of heaven and started to rule all the worlds peacefully.
Asura guru Shukracharya suggested Bali that he should perform “100 Ashwamedha Yagna” to make his place permanent as the king of all the worlds.
Bali ordered for the preparations for it.
Indra was very sad as Bali was gaining popularity and he lost his heaven. Indra’s mother Aditi saw her sons plight and prayed to Lord Maha Vishnu.
When Maha Vishnu appeared before her she asked to Vishnu to be born as her son and end King Bali.
Lord Vishnu said, “King Bali is a rightoeus man and he is destined to become the king of all the worlds, but because you have prayed for me and asked me this boon, very soon i will take birth as your son and do as you wished”.
After a brief period Aditi was pregnant with Lord Vishnu and she gave birth to a baby boy who grew up to be a handsome young boy but very short for his age, boy was very intelligent and he was named “Vamana”.
By the time Vamana reached the age of 5 King Bali performed 99 Ashwamedha Yagna and just one more Yagna will make him the king of the worlds.
Vamana’s thread ceremony was performed at his age 5 and he went out to do biksha as part of the ritual and reached the place where Bali was performing 100th Yagna.
Seeing the radiant boy at the yagna King Bali stood up from the yagna and stepped towards him, Shukracharya immediately recognised Maha Vishnu and warned Bali not to approach him and talk to him but Bali was very attracted towards boy and went to him.
Bali said to the boy, “I am honoured to have you here at the yagna, I give alms to anyone who comes to me today please ask me what do you wish to have.”
Before Vamana could speak Shukracharya interrupted Bali and took him aside and told that its Lord Vishnu who came in the form of a brahmin boy and will destroy you if you grant him anything.
Bali was happy to know that its his god who came to him and asking him to give something, nothing could be more satisfying and more precious for him in his life.
Not caring the warning of his guru Bali went to Vamana and asked him to wish for anything he want.
Vamana smiled at Bali and said “I just need 3 steps of land measured by my feet”.
Bali was amused by such simple wish laughed and said “I grant you what you asked”.
As soon as Bali said that Vamana started to grow in size and kept on growing to such a size that he covered whole earth with one step, sky with another feet and nothing was left to put his feet on to get the third promised step.
Vamana asked where do i put my feet for the third step?
Bali awestruck by the might of lord vishnu was in tears watching him and said, “I offer you my head to step on”.
Vamana smiled and put his feet on Bali’s head and pushed him down to patala.
All the gods were happy with the event and got hold of the heaven again.