Question: What nationality is Casimir I, Duke Of Cieszyn's father?
Sentence (from "Mieszko I, Duke of Cieszyn"): Mieszko I of Cieszyn (also known as Mieszko I of Opole; 1252/56 – by 27 June 1315), was a Duke of Racibórz during 1282–1290 (with his brother as co-ruler) and the first Duke of Cieszyn since 1290 until his death.
Relevant evidence: No