As the king of the gods in the ṛg Veda (see ṛg Veda), Indra's (see Indra) primary task is to establish order. This he does in various ways. He frees the cows from the Panis (see Panis)—the pre-Aryan (see Aryans) demons of India, and he does so by killing the dragon demon Vrtra (see Vrtra) and Vrtra's mother (see Diti). The Panis and the dragons both symbolize the “restraining” cultures that attempted to prevent the Aryan conquest of India. Energized by soma (see Soma) and using his thunderbolt to kill the asura (see Asuras) Vrtra, who had enclosed the waters, Indra freed the waters and brought forth the sun and light and the new order.
In the Mahabharata (see Mahabharata) we find a quite different Indra. The king of the gods is now king in name only and has limited powers. Anxious that his enemy Tvastr (see Tvastr), the architect of the gods, has created the three-headed son Tri'siras (see Tri'siras) to overpower him, Indra slays the demon with his thunderbolt. In revenge, Tvastr creates the dragon Vrtra, who defeats Indra—swallowing him and his whole world. It is only with the help of Visnu (see Viṣnu) and Siva (see Siva) that he and the world are freed.