The Umachal rock inscription is one of the earliest epigraphic sources discovered in Assam. Dated to the 5th century, the rock description was discovered in the north-eastern slopes of the Nilachal Hills (called Umachal), near Guwahati city. The artifact is dated primarily on the basis of the identification of the named Surendravarman with Mahendravarman (fl. c470-494) of the Varman dynasty. The script is in the eastern variety of the Gupta script and the language is Sanskrit prose. Though the Nilachal Hills is known for the Kamakhya Temple, a shakta/tantra site, this temple was for Balabhadra, a god of the Vaishnavite pantheon.