Elizabeth of Frankopan (Slovene: Elizabeta Frankopanska, Croatian: Jelisava Frankopanka, Hungarian: Frangepán Erzsébet, 1386–1422 or 1423), was the first wife of Frederick II of Celje, son and heir to Count Hermann II, Ban of Slavonia. By virtue of her marriage, she became the sister-in-law of the Hungarian Queen Barbara of Celje. Her marriage was troubled by disagreements with her husband, and in 1422 or 1423 she was found killed in her bed. The main suspect for the murder was her husband, who later married Veronika of Desenice, a woman of humble origin. The affair deteriorated the relations between the Houses of Celje and Frankopan, and led to a long-lasting feud between Elizabeth widower Frederick and her cousin Ivan of Frankopan. In the 19th and 20th century, Elizabeth's fate became th