Chandra Gupta II, the Sun of Power ("Vikramaditya"), ruled from 380 until 413. Only marginally less successful than his father, Chandra Gupta II expanded his realm westwards, defeating the Saka Western Kshatrapas of Malwa, Gujarat and Saurashtra in a campaign lasting until 409. Chandragupta II was succeeded by his son Kumaragupta I. Known as the "Mahendraditya", he ruled until 455. Towards the end of his reign a tribe in the Narmada valley, the Pushyamitras, rose in power to threaten the empire.