The Vamana Avatar is the first incarnation of Lord Vishnu as a human and the fifth of the Dasavatars. In the Vamana Avatar Lord Vishnu incarnates as Mahabali, the grandson of Prahlada, a great ruler who is loved by his people. Mahabali learns the Vedhas from his grandfather Prahlada and from the great Asura teacher Shukracharya.
Mahabali performs severe penance to please Lord Brahma. Lord Brahma grants him invincibility against Indra. Subsequently, Bali defeats Indra and takes over the heavens. However, Bali remains always righteous and is devoted to Lord Vishnu. Indra begs Lord Vishnu to help him.
Lord Vishnu incarnates as the son of Aditi and Kashyap, who performs his sacred thread ceremony and teaches him all the scriptures.
Meanwhile Mahabali has performed 99 Ashwamedha Yagna and has to perform just one more yagna after which he can be crowned as the King of the Gods.