Even in the company of her peers – Queen Elizabeth I of England, Queen Christiana of Sweden, the empress Maria Theresa – Catherine the Great stands out as an empire-builder, a larger-than-life, exceptionally astute, lucky and energetic politician. One of only three Russian rulers to be awarded the sobriquet ‘the Great’, Catherine, like Peter the Great, polarises biographers. Most historians who compare the Russia she inherited (or usurped) in 1762 with the Russia she bequeathed in 1796, and who weigh the enormous odds (hostile neighbours, a reactionary aristocracy and clergy, an enormous country with ruined finances, no roads and a resentful enslaved peasantry), end by adulating her. Puritanical or sensationalist biographers, however, conclude that she was a monster: the fifteen-year-old minor German princess from hell, who eventually with her lovers’ help murders her husband to grab a throne and – Machiavelli in the mornings, Messalina in the afternoons – devours her neighbours (Poland, the Crimea and Georgia), bankrupts her country with her palaces and furnishings, writes reams of derivative political treatises, edifying fairy stories and self-justifying love letters, neglects her bastard children, tortures her enemies and conducts a relentless public relations exercise so that Diderot, Voltaire and Grimm declare her to be the model of an enlightened ruler even while she bans and burns their works.

There is no doubt, however, that the Catherine the Great of sensational biography has taken on a life of her own. She was a philosopher’s dream: a monarch who treated them as equals. Few philosophers (and, surprisingly, Rousseau was one) remembered the fate of Seneca and decided to