Question: What is the date of death of Prince Harald Of Schaumburg-Lippe's mother?
Sentence (from "Heinrich Donatus, Hereditary Prince of Schaumburg-Lippe"): On the death of his father, Philip- Ernst, Prince of Schaumburg- Lippe, Alexander inherited the title Prince of Schaumburg- Lippe, while his son became Hereditary Prince.
Relevant evidence: No