Isotta is the Italian form of Isolde, a name of possibly Germanic origin, composed from the elements “ice” (is) and “battle” (hild). Other forms of the name include Yseult (French), Izolda (several of the Slavic languages), and Isolda (Spanish, Portuguese, Czech).
In The Decameron, Isotta appears in the sixth story of the tenth day, whose theme is magnanimity of character. She and Ginevra are the 15-year-old twin daughters of Messer Neri degli Uberti, a poor but noble knight who’s moved from Florence to Castello da mare di Stabia to be under the protection of King Charles I of Sicily (later only of Naples). He buys a piece of property, builds a nice, comfortable home, and creates a beautiful garden.
One day King Charles and four friends privately dine with Messer Neri in his garden, and the King is amazed is see these ethereally gorgeous young ladies. He’s even more fascinated as they wade into the fishpond to catch fish for supper, and passionately lusting for them when he sees their thin white garments clinging to their bodies from the water. Before they depart, they sing for the guests.
King Charles not only falls in love with both girls, but schemes to steal them away from their father so he can marry both of them. When he reveals his secret passion to his friend Count Guido, he’s rebuked severely. Count Guido tells him he’s acting like a horny little boy, not the wise old king he’s supposed to be. He also tells King Charles it’s really mean and disloyal to do such a thing after Messer Neri honoured him so much, even in his much-reduced financial state, and trusted him enough to let him see the girls in such an immodest state of dress.
King Charles realises the painful truth of these words, and rids himself of his foolish fancy by bestowing magnificent dowries upon them and marrying them off to noble knights and barons as if they were his own daughters. Isotta marries Messer Guiglielmo della Magna, and Ginevra marries Messer Maffeo da Palizzi.
Ishmael comes from the Hebrew Yishmael, meaning “God will hear.” I love this name for the same reason I love other unfairly-maligned Biblical names like Vashti, Jezebel, and Esau. Ishmael was actually a pretty popular Jewish name until Rashi slandered him in the 11th century. Just look at the straight Biblical text, and you’ll see he’s not some evil, mean, tricky, anti-Semitic monster. That was all added in later by commentators with a biased, Islamophobic agenda and a determination to assert their supremacy. Seriously, he’s not some obvious villain like Haman or Amalek.