William Prideaux Courtney, 1911 Encyclopædia Britannica, Volume 28… (1911)
“ The Mysterious Mother, a tragedy too horrible for representation on any stage, was never intended for performance in public, and only fifty copies of it were printed at Strawberry Hill. By Byron, who, like Horace Walpole, affected extreme liberalism, and like him never forgot that he was born within the purple, this tragedy was pronounced “of the highest order.” Several of Walpole’s antiquarian works merit high praise. ”
