Joanna (The Crusade)

Lady Joanna was the sister of King Richard I of England. While they both spent time in Palestine, Richard I tried to arrange to marriage between his sister and Saphadin in order to broker a peace between the English and Saladin's people, the Saracens. Joanna herself, however, very much opposed the plan and refused it. (DW: The Crusade)

Behind the scenes
Historically, the real Joanna had the full title of Joan of England, Queen of Sicily. Kamelion impersonated another of the historical Joanna's brothers, John of England, in The King's Demons.