But Devajammani soon found herself recruited for a more momentous cause - to publicise and promote the smallpox vaccine. And her unwitting role was captured in a painting commissioned by the East India Company to "encourage participation in the vaccination programme", according to Dr Nigel Chancellor, a historian at Cambridge University.
The portrait, an arresting rendition in oil on canvas, was last offered for sale via Sotheby's auction house in 2007. The woman on the left, he believes, is the king's first wife, also named Devajammani. The marked discoloration under her nose and around her mouth is consistent with controlled exposure to the smallpox virus, Dr Chancellor said.