The Vamana Avatar is the first Avatar in which Lord Vishnu incarnated as a human. This is the fifth of the Dasavatar, where Lord Vishnu incarnates as a dwarf to protect Indra. ['Vamana' in Sanskrit means dwarf]
The Vamana Avatar starts with Mahabali the Asura King. Mahabali was the grandson of Prahlada and the son of Virochana. Mahabali was a a great ruler and his people loved him. The people were very happy and prosperous under his rule. He was taught the Vedhas by his grandfather Prahlada and after that by his teacher Shukracharya. [After the churning of the ocean, when the Devas had taken the Amrit, Indra had killed Bali. Shukracharya brought back Bali to life, with the help of his mantras and power.]
Mahabali performed severe penance to Lord Brahma. Finally Lord Brahma appeared him, 'My Lord!' Bali said bowing before Lord Brahma, 'The people are always afraid of Asuras. I want to show the world that we are good. I want to have the power equal to Indra. I also should not be defeated in battle, sir!'
Lord Brahma sensed that Mahabali was a righteous man, meant for great things. Without asking any questions, he granted Mahabali his boon.
Shukracharya was a very good teacher and a very good battle strategist. With his help, Bali soon conquered the three worlds. Bali defeated Indra, the King of the Gods and took over the heavens. However Bali aided by his Guru was always righteous and was devoted to Lord Vishnu.
Shukracharya once called him, 'Bali! You have now conquered the three worlds. However if you wish to always be the Lord of the three worlds, you have to perform 100 Ashwamedha Yagnas. It is befitting that a king like you should perform the Ashwamedha Yagna, then you will always be the king of the 3 worlds.'
Bali who respected his teacher nodded his head and started about making preparations for the Yagna. Preparations were going on full scale.
Meanwhile, elsewhere Indra was lying dejected. Bali had not only defeated him, but was also showing the world, how a great ruler should behave! Bali was a good king and people loved him. Indra was actually feeling jealous of him. Indra had a feeling that all the Gods would also be on the side of the Asura – Bali.
He was sitting beside his mother Aditi in his father – Kashyap's hermitage. Aditi looked at her son and asked him. 'What is the matter son? You look unhappy...'
Indra looked at his mother and said quietly, 'Mother, it is Bali...'
Aditi looked at his son, waiting for him to explain.
'Mother, not only did he manage to defeat me, he is such a good king! People will always say that I am not that good a king as him...' Indra said angrily, 'They will compare me to that Asura and say he is better... I cannot bear it...' He said burying his hands in his lap.
Aditi looked at her son and took pity on him. 'I will see what I can do...But you have to promise me son that you will be a good king and not be hasty and act rashly henceforth...'
Indra looked at his mother, wondering what she could do. But Indra did not doubt even for a minute that his mother would solve his problem.
Aditi prayed to Lord Vishnu and started performing penance to invoke Lord Vishnu. After some time Lord Vishnu appeared before Aditi, 'Aditi! Open your eyes!'
Aditi opened his eyes and bowed to Lord Vishnu. Lord Vishnu spoke, 'Why did you pray to me, Aditi?'
Aditi said, 'There is nothing you do not know. You know that Bali has taken over my son's kingdom...'
Lord Vishnu interrupted softly, 'Aditi, Bali is a great man and he is good devotee and he deserves to be the Indra...'
Aditi took a deep breath and spoke again, 'My Lord! I have no doubt, Bali is a fit king. But are the other Asuras fit to rule? I am sure the other Asuras would fall to their old cruel ways and go back to hurting people...Is that what you wish?'
Lord Vishnu looked at Aditi thinking something, 'Well what do you wish?'
Aditi smiled, 'I wish that you are born as my son to end Bali's menace...'
Lord Vishnu smiled, 'Bali is not a menace. But there is one thing. Bali is destined to be the Indra.' Aditi looked at Lord Vishnu with fear. 'But... not just yet. It will be after some time.' Lord Vishnu said smilingly.
'I will take care of this. I will be born as your son, Aditi.' Aditi left home a slightly happy woman.
Soon Aditi and Kashyap were the parents of a black, beautiful short boy. He was extremely intelligent and full of pranks and was the darling of the house.
In those days at the age of five, the sacred thread ceremony was performed, to send the children for their education. Vamana's sacred thread ceremony was also performed.
Meanwhile Mahabali had performed 99 Ashwamedha Yagna and had to perform just one more yagna after which he could be crowned as the King of the Gods.
The final Ashwamedha Yagna was about to be get completed, when the entire kingdom saw a handsome dark boy approach the throne. He looked radiant and looked as if he had mastered all the arts in the universe.
Mahabali felt a surge of love towards the boy. He got up from the throne and offered it to the boy and bowed before him.
'Sir! I am honoured that you have come to my hundredth Ashwamedha Yagna. I now feel it will be a success.' Mahabali said looking at the boy lovingly.
However Guru Shukracharya was looking at the boy suspiciously.
Mahabali said again, 'Sir! Today happens to be the day I give away any alms to any person. I will give you anything you want. Please...
'Mahabali!' Shukracharya interrupted. Mahabali turned around surprised. His guru never spoke out of turn. Something was surely wrong. He looked at his Guru who spoke quietly, 'I wish to talk with you, my Lord!'
'You wish to talk with me now, sir!' Mahabali spoke incredulously. The guru nodded curtly and went inside the main hall to a private room. Mahabali hurriedly apologized to the dwarf boy and went to with his Guru.
'Sir! What hap...' Mahabali asked in an agitated manner.
'Silence!' Shukracharya spoke firmly, 'The boy is none other than Lord Vishnu. He has come here on behalf of Indra. If you give him what he wants, all will be lost...'
However it seemed as if Mahabali heard only half of what his Guru had said. 'Lord Vishnu...! He looked like a man in a daze. 'My Lord has come here to ask something from me...Than I must go...' He said going towards the door.
'Stop! You will do no such thing' The guru thundered, 'Will you disobey your guru and do what your enemy wants...'
'There is no rule as far as my Lord is concerned. And...' Mahabali looked with loving eyes, 'He has come to ask something from me...I will give him anything...' Mahahabli said with a simple devotion, from his heart.
'You disobeyed me!' Shukracharya said angrily, 'You will lose your all your splendour, Mahabali!'
Mahabali listened to the sages words and remained unchanged. It did not matter to him anymore. He looked at his Guru, 'Sir! I am not afraid of anything that will happen from giving my Lord what he wants'
Saying thus Mahabali walked out of the room followed by a furious Shukracharya.
Mahabali went to the boy again and spoke lovingly, 'Sir! We were rudely interrupted...For that I am sorry. As I was saying, today is the day I will give anything to any person who comes asking from me. What is your wish sir?'
The dark boy looked at Mahabali quietly, 'I want three steps of land, measured by my feet!'
Whatever Mahahbali had expected this was not it! He expected the boy to ask for his life, his...anything but not this...this was simple...too simple. He almost laughed. 'Three steps! That is all you want! I will give you....'
The boy interrupted, 'If any person cannot be satisfied by three steps, of land there is nothing much he can be satisfied with, your Majesty! That is all I wish...'
Looking at the dark boy, the king felt the same magnetic effect. He nodded his head, 'Anything you wish sir!'
As soon as Mahabali uttered these words, Vamana grew. Vamana grew...and grew and grew. He grew so huge, that from where Bali stood, he could see only the boy's feet, nothing else. The boy had grown so huge that the earth itself seemed to measure up in his one step!
Next the boy lifted his other leg and measured up the entire skies with his other step! [The avatar where Lord Vishnu grew to such a huge size is called as Trivikrama Avatar]
Mahabali stood there astounded watching the Dark Lord's brilliance! The boy called Mahabali. 'Oh Great King! You promised me three steps... I have measured the earth and the skies in two steps. I have nowhere to keep my third step. Where shall I keep my third step?'
Mahabali heard the boy and smiled, 'My Lord! I am not someone who breaks his promises. I offer my head as your third step my Lord!'
Lord Vishnu gave a beautiful smile, a melancholy smile and kept his third step on the Asura's head. The Asura was pushed to the Nether world [Paatala] by the force of the third step on his head.
Thus Mahabali was removed from his splendour of being the king of the Three Worlds and was pushed to the Nether worlds....
Indra and the other Devas came back to their skies grateful that they had got back their kingdom. They were happy.
However Lord Vishnu was perturbed. Mahabali had been his true devotee. He had not faltered even when his guru had warned him. He remained true to what he had said...Lord Vishnu went to the underworld.
In the underworld, Mahahbali was rebuilding his kingdom. He did not once regret the fact that he was back in the underworld...He had served his Lord and had kept his promise. He was happy. He saw a dark man approaching him. 'Your majesty! I hear you are rebuilding your kingdom. I will be your watchman your majesty! I will protect you and be part of your army!'
Mahabali looked at the dark strong young man. He agreed. The man stayed along as his watchman.
Meanwhile a very beautiful woman also came up to Mahabali. She looked powerful and graceful at the same time. She said to Mahabali, 'Your Majesty! My husband...he has gone to fulfill some errands and is not yet home. I feel lonely without him. I also need protection. I heard that in Mahabali's kingdom, you look after everyone like your own children. Please give me protection too!'
Mahabali was moved when he heard the woman. He said, 'Lady! You are like my sister to me1 Please come and stay in my palace. You can stay there as long as you wish!'
The lady thanked Mahabali. Very soon the Nether world became a very prosperous place. People lived very happily and without any worries.
Soon Mahabali relied on the watchman and his sister's counsel heavily. His kingdom was flourishing.
One day Mahabali heard the lady saying some prayers. 'Whom are you praying for?' Mahahbali asked the woman.
The woman turned and looked at Mahabali and said, 'You are my brother! I am praying for you!'
Mahabali was moved and again said, 'Whatever you want, I will give you, my sister!'
The lady smiled, 'I want my husband, Mahabali. You are the only one who can give it to me...'
Mahabali looked confused, 'Me..give your husband...?'
The lady pointed to the watchman, 'That is my husband...'
Mahabali blinked and stared as the two people vanished and there stood Lord Vishnu and Goddess Lakshmi in their places. Mahabali was flabbergasted that the great Lord had been his watchman! And that the Goddess of Fortune – Lakshmi had been with him all these days!
Lord Vishnu spoke, 'Your devotion dragged me here Mahabali! I had to be with you...'
Mahabali fell to his feet and looked at the Lord. The Lord continued. 'After this Indra's rule, you are the next Indra...That is my promise. Be a good ruler, my son!'
Mahabali then turned to the Goddess, 'I am sorry for keeping your husband from you, sister! Take him and go back!'
The goddess smiled, 'Thank you! And you did not keep him! He always is with people who love him most! May you always be prosperous...brother!'
Saying thus the two of them vanished to went back to Vaikunta. The bond between Mahabali and Lakshmi is said to be one of the reasons for celebrating the Raksha Bandhan, where the sisters prays for the welfare of the brothers and the brothers protect the sisters from any harm!