Ushas is a goddess linked with and sometimes identified with
the dawn in the Vedas, the oldest and most authoritative Hindu religious
literature.
Her presence is therefore related with the regularity of the
cosmic order, as she is depicted as illuminating the route for the sun and
driving away darkness and evil.
Ushas is famous not for what she does—she is a minor
divinity who appears in just a few Vedic hymns—but for being one of the few
goddesses in the Vedas.
One of the reasons for the belief that the great Goddess,
one of the three primary goddesses in later religious life, has her origins in
indigenous goddess worship is the near lack of female divinities in the Vedas.
See David R. Kinsley's Hindu Deities, 1986, for further information
about Ushas and all the Hindu goddesses.