Eleanor of Aquitaine

Eleanor of Aquitaine was among the notable women of Earth's history who were invited by to join MADAM. In her invitation, Missy commended her for how she dealt with the Fair Rosamund, which involved the "cup of poison/dagger thing".

She left MADAM along with all of its other members after the Twelfth Doctor, undercover as Circe, antagonised Missy into saying something sexist. (PROSE: Girl Power!)

Behind the scenes
In the real world, Eleanor of Aquitaine was the mother of Richard I of England and John of England and the consort of, the first Plantagenet king.