Dido Belle: In Scotland's Scone Palace hangs a portrait of Lady Elizabeth Murray and a black woman mistakenly thought to be her servant, but who was in fact her cousin, Dido Elizabeth Belle, the illegitimate daughter of a naval captain and a slave. The archives at Kenwood House provide clues to Dido's life, while an 18th-century cotton mill reveals much about the impact of slavery on the fashion of the day.