Introduction
Sumali is a Rakshasa chief, the father of Kaikesi and Prahasta and the maternal grandfather of Ravana.
This article primarily follows the Valmiki Ramayana. Where a well-known detail comes from a later retelling or tradition, the article identifies it.
Family
Exile from Lanka
In the Uttara Kanda, Sumali and his brothers, Malyavan and Mali, ruled Lanka until Vishnu defeated them. Mali was killed, and Sumali fled with his family to the netherworld (Rasatala).
The rise of Ravana
Sumali's wife was Ketumati, a daughter of the Gandharva woman Narmada. He planned the marriage of his daughter Kaikesi to the sage Vishrava so that his grandsons could win back Lanka. He encouraged Ravana to take the city from Kubera.