Many centuries ago Kerala was ruled by an Asura (demon) king known as King Mahabali who was wise, benevolent and judicious ruler and loved the people of kingdom. It is believed that under his kingdom kerela prospered and all his people laid a peaceful and harmonious life. It was a period of peace, prosperity and contentment and there was crime or violence in the state. Each indiviual was treated equal to other and there was no poverty.
His kindness and love became popular all over. When his kingdom extended to the heavens and the netherworld, all the gods felt challenged and afraid about his growing powers. On this all the Gods went up to Lord Vishnu and pleaded him to curtail Mahabali’s powers. Lord Vishnu sympathized them and agreed to stop the reign of King Mahabali.
Then Lord Vishnu took the avatar of a poor and dwarf Brahmin, Vamana and visited King Mahabali when he was doing yajna. At that time the King gave boons to the Brahmins. After talking to the dwarf brahmin’s King Mahabali was pleased with his wisdom and King Mahabali granted him a wish and promised to give him whatever he asked for. On which Sukracharya King Mahabali’s Guru, warned him against it as he had realized the brahmin was no ordinary person. But King Mahabali’s ego came in between and he did not obeyed his guru. Vamana, the brahmin asked for as much land as could be covered by his three steps as his gift. The king was surprised and puzzled to known Vamana’s wish but, still he granted the wish.
Then suddenly little brahmin Vamana began to grow and became giant so grew so huge that with his first step, he covered the entire earth. Then with the second step, he covered both heaven and hell. With these two steps Vamana had covered the entire cosmos, now he had no place for his third step on which he asked the king for a place for his third step. King realised that the Vamana was no ordinary Brahmin. But the king had to keep his words therefore King Mahabali asked Vamana toput his third step on his head.
Vamana third step pushed the king to the netherworld, but before that Lord Vishnu granted him a boon (vardan) that since the king was attached to his kingdom and his people, he was allowed to return once a year to his people and kingdom.
Onam is celebrated to the marks this homecoming of King Mahabali. On this day the grateful people of Kerala pays a glorious tribute to the memory of this king who gave his all for his people.
In 2018, Onam will be celebrated on 24th August 2018.