Rakshasa kingdom refers to the territory of Rakshasas who were a tribe, mentioned along with others like Devas (including Rudras, Maruts, Vasus and Adityas), Asuras (including Daityas, Danavas and Kalakeyas), Pisachas, Gandharvas, Kimpurushas, Vanaras, Suparnas, Kinnaras, Bhutas and Yakshas. Rakshasas were described to have large bodies, probably due to their continuous life in cold climates over snow-covered mountains. The forefathers of the famous Rakshasa king Ravana lived along with the Yakshas. The Yaksha king Kubera was the elder brother of Rakshasa king Ravana. Ravana had many sons among Gandharva wives. The two epics Mahabharata and Ramayana and many Puranas attest that Rakshasas, Yakshas and Gandharvas were related and had inter-marriages.