Question: What is the date of death of Mieszko I Tanglefoot's mother?
Sentence (from "Mieszko I Tanglefoot"): He was also Duke of Silesia from 1163 to 1173 (with his brother as co-ruler), Duke of Racibórz from 1173, and Duke of Opole from 1202 (as Mieszko I Tanglefoot).
Relevant evidence: No