This is the story of Dido Belle, whose adoption by an aristocratic family challenged the conventions of 18th century England Dido Belle was the illegitimate, mixed-race daughter of a Royal Navy captain and a slave woman, adopted by the Earl of Mansfield. As Lord Chief Justice of England he would preside over the drowning of 142 slaves by a shipping company. This is the story of a family that defied convention, the legal trial that exposed the cruelties of slavery and the woman who challenged notions of race at the highest rank.