Question: What is the date of death of Alexander Hochberg's mother?
Sentence (from "Alexander Hochberg"): As an heir of once mighty Silesian ducal family of Dukes von Pless, Alexander (officially styled "Alexander Friedrich Wilhelm Georg Konrad Ernst Maximilian Graf von Hochberg, baron zu Fürstenstein, 5th Fürst von Pless") had been a Polish citizen following the annexation of Upper Silesia and Pless by Poland in 1921.
Relevant evidence: No