Onam is typically celebrated for 10 days beginning the first day of the Malayalam month of Chingam. Onam is actually short for Thiruvonam, the nakshatra or the star associated with Vishnu.
In popular mythology, onam marks the annual return of Mahabali to pay a visit to his beloved subjects on earth from the underworld, where he was pushed into by Lord Vishnu.
According to the Bhagavata Purana, which narrates one version of the story, the asuras, led by King Mahabali, had conquered the three worlds, having driven out the devas from the heavens. Bali, the asura king then started to perform an ashwamedha yagna or a horse sacrifice to consolidate his sovereignity.
Meanwhile, Aditi, Indra’s mother, who was upset over her son losing out to Mahabali, prayed to Vishnu. Hearing her prayers, Vishnu took birth from her womb to help her son Indra reclaim his position as the lord of the heavens.
Taking the form of a dwarf brahmin, Vishnu arrived at the horse sacrifice, where Mahabali was making generous donations to all the needy Brahmins. The story goes that the puny Vamana asked the king for land that could be measured in three paces of his foot.
Even when warned by his guru Shukracharya that the dwarf was none other than Mahavishnu in disguise, Mahabali decided to go ahead and grant the Brahmin’s wishes. But once Mahabali agreed to gift him three paces of land, it is said Vamana the dwarf grew into a giant of cosmic proportions and took gigantic strides to measure the earth and the heavens with his two steps, asked Mahabali where he could keep his third and last step. As there was no place left in the Universe for Vishnu to measure his third pace of land, the defeated Mahabali surrendered by offering the god his own head.
From this point, the story differs slightly across versions, of which there are many. According to one version, Vishnu kept his foot on Mahabali’s head and pushed him into the netherworld, which he was asked to rule thereafter. In another version, Vishnu does not push him into the netherworld, but rather asks him to reside and rule it and promises him that he would get to be Indra in another yuga.
The Bhagavatha Purana says that, despite being a virtuous king, Mahabali was punished because power and pursuit of material wealth had corrupted him and destroyed his humility. In his arrogance, he had even overlooked his guru’s advice to grant the Brahmin dwarf the gift he demanded, knowing very well the midget was none other than Lord Vishnu.
Now, many of you may be aware of the story.
But, how does the Mahabali-Vamana avatar myth actually connect to the onam festival?
Surprisingly, not all textual versions mention the request by Bali to visit his land and his favourite subjects every year. The bit about Mahabali coming up to the earth every year, appears rather to be a folk extension to a Puranic story.
And Onam, that celebrates the return of Bali to the earth, is essentially a folk festival that celebrates the completion of paddy harvest. On this occasion, the just and egalitarian rule of Bali is remembered in the Malayalam folk songs that are sung to welcome the king.
Apart from the performance of folk arts and sports such as the kathakali and the famous boat race, other folk motifs include the use of pyramid-shaped four-sided blocks made of clay called Onathappan, that are used to symbolically represent a local deity named Thrikkakara appan or Vamana Vishnu. According to some, these pyramidical clay blocks represent Mahabali or Maveli as he is fondly referred to by the locals. This an-iconic representation of the gods definitely points to very ancient folk customs.

Interestingly, the celebration of bali is not restricted to Kerala. King Bali is remembered and hailed in several parts of western and southern India on the fourth day of Diwali as Balipadyami or Balipratipada, marking the end of the summer harvest. In fact, the farmers of Maharashtra pray every year for the return of the fair and just rule of King Bali.
So, in a sense, the annual return of Bali to earth, from the nether land seems to suggest a symbolic association with the fecundity of the land that is renewed every year after the monsoons, when the Onam festival falls.
How modern narratives interpret the myth…
In modern narratives, the mass popularity of the legendary Asura king punished rather unduly by Vamana Vishnu, has led the story to be interpreted as a conflict between two different cultures, where an Aryan tribe, represented by their god, established supremacy over Bali, the just and fair king of a non-Aryan tribe.
This version is in sync with other subaltern narratives where the Asuras have been understood to be the oppressed class with the Devas being envisioned as the upper caste oppressors.
Moreover, the vamana story, also comes across as a sort of a prequel to the story of Parashurama, another avatar of Vishnu, who, despite being a Brahmin, took to arms to end the tyranny of the Kshatriyas or the ruling class. According to a legend that links both these stories, the entire western coast of India, is believed to have been retrieved from the sea by Parashurama with his axe, to relocate the Brahmin community. And Onam celebrates the creation of Kerala by the sage.
In this myth, the relocation of Brahmins by Parashurama could have involved the displacement of the existing residents of the Western coast, probably pushing them south. The movement of people further down (south) is possibly reflected in the story of Bali who is pushed down (into the earth) by a Brahmin.
While these stories do seem to hint at conflicts over land leading to possible displacement of some groups of people, author Nandita Krishnan, in her work, Book of Vishnu has proposed a completely different interpretation of the myth.

She points out that the vamana avatar story has its seed in the RigVeda and the Shatapatha Brahmana, a Vedic ritual text. In these texts, Vishnu was considered an aspect of the Sun and counted among the 12 adityas or solar deities.
The sun takes three strides across the sky through the day – appearing at the horizon at sunrise, touching the zenith at noon and disappearing below the horizon at sunset. Similarly Vishnu in his Vamana avatar has been shown to take three strides across the universe, covering the earth, heavens and the underworld.
Nandita suggests that Onam celebration is a symbolic representation of the harvest which is welcomed with a thanksgiving offering ‘bali’, after the passage of a hot summer as depicted by the solar deity, Vishnu. So, just like Pongal or Baisakhi, Onam marks the celebration of the harvest, which was made possible by the Sun, to whom mahabali or a great offering is made.
Now, that’s an interesting possibility!