The story begins with King Vijaya who was sent into exile on account of his insolence by his father Sihabahu, king of Lala. King Vijaya landed in Sri Lanka with seven hundred companions exhausted with the journey. They instantly fell in with the tutelary divinity of the island. There Lord Vishnu or Uppalavanna was sitting in the form of a devotee at the foot of a tree for the purpose of receiving them and providing them with a counter charm against enchantment.
When the companions of King Vijaya questioned where they landed, Lord Vishnu then told them the name of the island. He then besprinkled them with water out of his pitcher, tied charmed threads round their arms, and vanished.
After he disappeared then instantly a Yaksha female attendant appeared in the form of a dog. One of the companions of Vijaya followed her as he thought he could get to know for a village. He found himself in the presence of her mistress, the Yakshini Kuveni who was sitting spinning under a tree near a tank.
When he saw this tank and the lady sitting beside it, he bathed and drank from it and collected edible roots with lotus flowers. Then Yakshini Kuveni said he is her prey and the companion was enthralled. As he had the charm thread of Lord Vishnu so she could not bewitch him. She asked him to give the holy thread but he didn't. She therefore laid hold of him and cast him bellowing loudly into an underground cave.
In this manner all the seven hundred companions of Vijaya was trapped and imprisoned in the cave. When none of the followers came back then Vijaya became anxious. He went after them and also arrived at the tank. Then he saw that there were no footsteps of any of the men those who have gone. Vijaya saw the anchoress, and asked her if she had seen any of his companions. She said she did not know and asked the Prince to drink and bath. Vijaya perceived that she was a Yakshini and ordered her to free his attendants nor he would put her to death.
Struck with terror she begged for her life and promised to give away the kingdom and work as per as his wishes. Vijaya made her to swear an oath and she freed all his attendants and supplied them all with abundant food and clothing. She changed her form a maiden and was married to the king Vijaya.
Later when king Vijaya married the daughter of the Pandava king of Madhura then he left the Yakshini. Kuveni met her death by the hand of one of her Yaksha relations, who was enraged on account of her treachery.
Thus Mahavanso or Mahavamsa was an important epic poem in Pali language.