Question: When was the British adventurer who has his portraiture commissioned by Johnny Jonas born? 
Sentence (from "David Mayer de Rothschild"): He is a member of the Rothschild family, the youngest of three children of Victoria Lou Schott (born 1949) and Sir Evelyn de Rothschild (b. 1931) of the Rothschild banking family of England.
Relevant evidence: No