The Churning of the Ocean of Milk

Weakened by a curse the irritable sage Durvasa placed on Indra after the god carelessly disrespected a garland the sage had offered him, the devas find themselves losing ground to the asuras and appeal to Vishnu for help. Vishnu counsels an unlikely alliance: churn the cosmic Ocean of Milk together, promising the treasures and the nectar of immortality, amrita, hidden within it to both sides, then find a way to keep the results for the devas alone. Using the mountain Mandara, uprooted and set upright in the ocean as the churning rod, and the great serpent Vasuki, wound around it as the churning rope, with the devas pulling at his tail and the asuras at his many-headed end, the two sides begin to churn the ocean between them.

As the churning intensifies, Mandara begins to sink for lack of a base, so Vishnu descends in the form of the great tortoise Kurma and positions himself beneath the mountain, bearing its full weight on his shell so the churning can continue. The strain first produces not treasure but poison: the deadly Halahala rises from the depths, threatening to destroy gods, demons, and the world alike with its fumes, until Shiva swallows it to protect creation, holding it forever in his throat rather than letting it pass further, which turns his throat permanently blue and gives him the name Nilakantha, the blue-throated one.

With the poison contained, the churning continues and yields a sequence of divine treasures in turn: the wish-fulfilling cow Kamadhenu, the goddess of fortune Lakshmi, who chooses Vishnu as her consort, and the divine physician Dhanvantari, who rises at last bearing the pot of amrita itself. When the amrita finally appears, the asuras seize it and a struggle for possession breaks out; Vishnu takes the form of the enchanting maiden Mohini, distracts and beguiles the asuras, and while distributing the nectar contrives to give it only to the devas, securing their victory and immortality.

One asura, Rahu, disguises himself among the devas and manages to drink a portion of the nectar before the sun and moon gods notice and alert Vishnu, who beheads him with his discus before the amrita can pass fully down his throat. Because the nectar had already reached his head, that portion becomes immortal even though his body does not, and the severed head, Rahu, and the still-mortal body, now called Ketu, are given a place in the heavens as the cause of eclipses, said to periodically swallow the sun or moon in revenge as they pass through their positions in the sky. The episode is one of the central cosmogonic events of Puranic Hinduism and a frequently depicted scene in temple sculpture across South and Southeast Asia.