Brahma, Vishnu, and Shiva, respectively Creator, Preserver, and Destroyer, constitute a trinity in Hinduism, as three aspects of the operation of the one creative substance. After the seventh century B. C., Brahma, declining in importance, became merely the creative agent of Vishnu.
Campbell defines Brahma’s structural role within the Hindu trimurti while noting his progressive demotion to subordinate demiurge beneath Vishnu.
, The Hero With a Thousand Faces, 2015thesis