Radha's rise is the clearest case of Hindu theology being changed by poetry rather than by philosophy. She is nearly absent from the Bhagavata Purana; Jayadeva's Gita Govinda in the twelfth century made her the erotic and emotional centre of the Krishna story, and the devotional traditions of Bengal, Braj and Rajasthan built themselves on that. Gaudiya Vaishnava theology, systematised by Chaitanya's followers in the sixteenth century, gives her a startling status: she is Krishna's own pleasure-potency, more essential than he is, and Chaitanya himself is understood as Krishna having taken on her state in order to feel what she feels. The relationship is deliberately illicit — parakiya, love outside marriage — because unauthorised love is held to be a purer sign of devotion than duty is. Conservative Vaishnava schools were uncomfortable enough with that to insist she is married to him after all, and the argument is old.