Ravana was son of Rishi Viswashrava and Nikasha. In his previous birth, Ravana and his brother Kumvakarna were the gatekeepers of Vaikuntha-Dham and their names were Jay and Vijay. One day Sanaka and other Rishis were insulted by Jay and Vijay. They could not allow the Rishis to pass the gate of Vaikuntha-Dham. Becoming furious in anger the Rishi cursed the two brothers that in their next life they will take birth as rakshas (demons) but Lord Rama would free them from that curse. Jay and Vijay born in the rakshas race and were called Ravana and Kumvakarna. Ravana defeated Yaksharaj Kuber, won over the three world and became the emperor of Swarnalanka. In the meantime, Lord Rama also took birth in Ayodhya to King Dasharatha and Kaushalya. Dasharatha had three wives – Kaushalya, Kaikeyee and Sumitra. Kaikeyee’s conspiracy put Rama into exile for 14 years. His wife Sita and brother Lakshmana accompanied him. In the Panchawati woods, the deceptive Ravana abduct Sita. Rama while looking for Sita met Hanuman, Jambuban and Sugrib. They came to know that Ravana had abducted her. Rama with the help of monkeys made a bridge in between Lanka (now Sri Lanka) and India and fought against Ravana’s army of demons. He killed Ravana’s 100 sons before executing Ravana
Ravana and his brother Kumvakarna were the gate keepers of Vaikuntha. They were cursed by the Sanatha Kumara rishis and born as demons in the next birth and Lord Rama would free them. Later in the Satya Yuga, Lord Rama was born. He went to exile with his wife Sita and brother Laxman. Sita was abducted by Ravana and Rama went to Lanka to free Sita. There Ravana was defeated by Rama.