A Royal Affair: George III and his Troublesome Syblings by Stella Tillyard

Royal shocker: some of the family sane

Mary Wollstonecraft travelled with intrepid Romantic curiosity to Scandinavia in 1795 and saw Christian VII of Denmark at first hand; she described him as "a notorious debauchee, and an idiot into the bargain". Christian was first cousin to George III, and what was wonderful about the inbred royal families of Europe was that so many of their members were almost sane. Perhaps one of the sanest was George III's sister, Caroline Matilda, who was posted off against her will, like a dynastic parcel, to be married to her cousin Christian in 1766.

Stella Tillyard does not mention the Wollstonecraft connection, but is utterly blameless here, for she has been busy learning to read Danish. Most British state documents of the time concerning Caroline Matilda were scrupulously destroyed, since they discussed not only what her Danish defence lawyer called her "limitless lust", but also possible evidence of British intervention in the internal affairs of another state, as they'd say: gunboats up the Kattegat.

A Royal Affair gives us a full account of the trouble caused to George III in the earlier years of his reign, when, like a certain later Lakelander, he had good cause to exclaim: "What a thing is an unruly family!" Tillyard's linked stories of Augusta, Caroline Matilda, and the Dukes of York, Cumberland, and Gloucester, are anchored by her explanation of the dilemma facing George, when, for the first time, press freedom and six siblings - some of them both pigheaded and sexually adventurous - combined to produce the situation now so familiar to us, where the private lives of royalty are also public property. Those used to an Alan Bennettish, endearing George, will find a much testier man here; he's more like the older brother who keeps telling you to take your elbows off the table.

In this superbly engrossing and revelatory book, Tillyard's detective instincts and clever narrative structure - noted before in her very well-received Aristocrats - work together to inform and delight. She writes with a strong and well-planned energy, and an occasional whiff of overwriting is more than compensated for by some refreshing Jane Austenisms: at Savile House, poor "Prince George was falling mutely, ponderously and helplessly in love." The fact that George's own love for the non-royal Sarah Lennox was hopeless gave an added bitterness to his dealings with his brothers, who would not do as they were told and marry into the muddy waters of European royalty, many of whom were already their relatives.

If there is a problem with this Royal Affair, it's that Caroline Matilda's Danish experiences are of such consuming interest that the parochial sexual misdemeanours of George's male siblings pale in comparison, like putting Catherine the Great next to Fergie. Edward Duke of York's adulterous shipboard love-letter to Lady Grosvenor - "I then lay down and dreamt of you, had you on the couch 10,000 times in my arms" - caused scandalised hilarity in the press, and censoriousness later when divorce courts became involved: the way was now open for abdication, toe-sucking and Tampax. The muddles are wearily familiar, as brothers who make imprudent marriages demand more dosh from the Civil List, and cause grief for a domestically inclined and morally impeccable sovereign.

Caroline's story, though, is one of a remarkable and unaccountably neglected social experiment, in which Enlightenment rationality and the baleful traditions of royal absolutism clashed to bloody effect. When, at 15, George's youngest sister was married to Christian VII, she found herself in a strange feudal world, where sacred divine right meant that the man whom Copenhagen saw roaming the brothels at night, making use of their services and then smashing them up, was also their absolute sovereign; yet so weak was he that he would sign documents meekly for anyone powerful enough to dominate him.

Caroline quickly bore a son to Christian, but then fell in love with Johann Struensee, the king's German doctor, a forceful and charismatic man who soon found his way to her bedchamber and to power over Christian. For a short, exhilarating time, Caroline and Struensee jointly held ultimate power in the state. Both were in favour of Enlightenment principles of equality, secularisation and freedom, and a puzzled Denmark found the old ways being swept away as Struensee tried to alter the foundations of the state. Even worse, the couple were bringing the little Prince up on Rousseau's ideas of child-rearing on natural principles: no shoes! There was now a daughter too, almost certainly Struensee's but being brought up as Christian's.

At length the forces of reaction moved against the pair with astonishing severity. Christian VII found other hands guiding his as he signed documents condemning them. As Queen, and a "daughter of England", Caroline was safe, but her children were removed and she was imprisoned in Hamlet's own castle at Elsinore. The British press threw up its horrified hands, and war with Denmark was imminent. According to Tillyard, though, both Struensee and Caroline were manipulated - in his case, possibly tortured - into signing confessions of their adulterous guilt. This made the British huffing and puffing less convincing, and Caroline was quietly removed to George's Hanoverian domains, without her children or her lover, whose right hand, and then head, were removed by an axe, and his body quartered. It was not long before Caroline, now only 23, died of scarlet fever and saved her brother much embarrassment.