In the Diwali tradition about Rama, the demon king defeated before the return to Ayodhya is Ravana. Rama’s victory over Ravana in Lanka ends the central conflict of the Ramayana and clears the way for Rama, Sita, Lakshmana, and Hanuman to return home.
Ravana is portrayed as the ruler of Lanka, a powerful rakshasa king with exceptional learning, devotion, and military ability, but also with destructive pride. The conflict begins after Ravana abducts Sita. Rama forms an alliance with Sugriva and the vanara forces, while Hanuman becomes a crucial messenger, warrior, and devotee.
The war is narrated in the Ramayana’s Yuddha Kanda, or Lanka Kanda, depending on the tradition. Rama ultimately kills Ravana with a divine weapon after a prolonged battle. He then installs Ravana’s righteous brother Vibhishana as ruler of Lanka before beginning the journey back to Ayodhya.
Dussehra, celebrated roughly 20 days before Diwali, is commonly linked to Ravana’s defeat and often features the burning of his effigy. Diwali instead emphasizes the joyful return and the lighting of lamps. Other Diwali traditions tell different victory stories, including Krishna’s defeat of Narakasura, so the Rama-Ravana account is important but not universal across India.