Son of Mahāsāgara, who was the king of Uttara Madhurā.
Upasāgara's elder brother was Sāgara, and when their father died, Upasāgara became his brother's viceroy. Having been suspected of an intrigue in the king's zenana, he fled to the court of Upakamsa in Asitañjano. There he fell in love with Devagabbhā, and when she was with child he married her and they lived in Govadhamāna.
Their children were the notorious Andhakavenhu-dāsaputtā.