Richard the Lionheart
Richard the Lionheart's mummified heart has been analyzed. I found this pretty interesting because in college I was enthralled by medieval British history. The novels and movies that feature him are all over the map as far as accuracy goes .... for instance, the Robin Hood movies/books always made him sound like a great king but he was actually a rather bad king: he probably spent a year out of the ten of his rule in England, he lost Jerusalem in the third crusade, he married his wife for her lands and didn't get an heir, he made life difficult for the Jews in England, and he practically impoverished his citizens by getting captured and held for a huge ransom.
He died from a crossbow bolt wound that went bad and his body was somewhat parted out, his heart being buried in Normandy. A 13th-century Bishop of Rochester wrote that Richard spent 33 years in purgatory as expiation for his sins, eventually ascending to Heaven in March 1232. - Wikipedia ;)
Some novels I read in which he made an appearance ... Ivanhoe ... The kings of vain intent ... The Lute Player. He's been portrayed in a lot of movies too, the most recent one (I think) being Robin Hood, but the movie that made the biggest impression on me was The Lion in Winter.