Upamaṅgu (Upamangu) was one of the sons born out of the womb of Gāṅdinī. His father was Śwaphalka (Swaphalka) of the Bṛṣṇi (Brishni) dynasty. Akrūra (Akrura) was the elder brother of Upamaṅgu (Upamangu).
In the Viṣṇu Purāṇa (Vishnu Purana), Upamaṅgu (Upamangu) was known as Upamadgu.