INDRA. In India the worship of the god Indra, king of the gods, warrior of the gods, god of rain, begins properly in the Ṛgveda, circa 1200 BCE, but his broader nature can be traced farther back into the proto-Indo-European world through his connections with Zeus and Wotan. For although the Ṛgveda knows a sky father called Dyaus-pitṛ, who is literally cognate with Zeus-patēr and Jupiter, it is Indra who truly fills the shoes of the Indo-European celestial sovereign: He wields the thunderbolt, drinks the ambrosial soma to excess, bestows fertility upon human women (often by sleeping with them himself), and leads his band of Maruts, martial storm gods, to win victory for the conquering Indo-Aryans.

In the Ṛgveda, Indra's family life is troubled in ways that remain unclear. His birth, like that of many great warriors and heroes, is unnatural: Kept against his will inside his mother's...