D4 The Empress and the English Doctor

As smallpox ravaged her empire and threatened her court, Catherine the Great took the momentous decision to summon the Quaker physician, Thomas Dimsdale, from Hertford to St Petersburg to carry out a secret mission that would transform both their lives. Caroline Sanderson talks to writer Lucy Ward about this extraordinary story of Enlightenment ideals, female leadership and the fight to promote science over superstition.