Henry FitzRoy , 1st Duke of Richmond and Somerset ( 15 June 1519 -- 23 July 1536 ) , was the son of King Henry VIII of England and his mistress , Elizabeth Blount , and the only illegitimate offspring whom Henry VIII acknowledged .
Henry FitzRoy , 1st Duke of Richmond and Somerset ( 15 June 1519 -- 23 July 1536 ) was the son of King Henry VIII of England and his teenage lover , Elizabeth Blount .