Bitter orange is a citrus fruit close to oranges, but very bitter and it must be cooked or candied to be taste good. The sweet orange (citrus sinencis), that we know of today, appeared only in the 15th century, and it was not found in cookery before the 16th century. So beware, when you read the word orange in a medieval text, it always refers to the bitter orange!
I heard a story once that a princess of Portugal who married into the English royal family served bitter orange marmalade out of spite to English people she didn’t like. Her guests had to eat it and pretend to like it because of her position. It seems several genuinely did like it, and thus eating marmalade became a custom in England.
Would you look at that, apparently I haven’t made this whole thing up. Princess Catarina de Bragança (who married King Charles II of England) is credited with introducing marmalade to England in the 1600s, along with the custom of afternoon tea. (So far I haven’t found any sources that say whether she did it out of spite.)
Kimchi and Justice 