What is "pushyamitras"

The Pushyamitras were a tribe who lived in Central India during the 5th century CE. Living on the banks of the river Narmada, they are believed to have posed a serious threat to the Gupta Empire during the late period of Kumaragupta I's reign. In inscriptions covering the events between 455 and 467 CE, Skandagupta, Kumaragupta's successor, emphasises his role in defeating the Pushyamitras as well as the White Huns.