Raychoudhuri drew this theory about the pedigree of the Guptas based on the Riddhapura copper-plate inscription of Prabhabati Gupta, daughter of Chandragupta II.
Prabhavati was the daughter of a Naga dynasty princess from northern India who had been made a consort of the Gupta emperor Chandragupta II when the Naga lands were overrun by Gupta soldiers.