Even the vast interior of Freemason’s Hall could not accommodate all who came to hear Portsmouth’s trial for lunacy.

John Scott, first earl of Eldon and Lord Chancellor, found Portsmouth’s case ‘the most painful business’ of his legal career.

Hurstbourne Park, the ‘perfect palace’.

Farleigh House, the Portsmouths’ other home in Hampshire.

Jane Austen’s family home at Steventon, where Portsmouth was sent as a boy.

Portsmouth’s younger brothers, Newton and Coulson, painted for their proud parents when they left Eton.

Urania, 2nd countess of Portsmouth – who would dare to cross this woman?

Urania’s favourite son, Newton.

Urania’s trusted friend, Reverend John Garnett.

Byron, the hopeless romantic, was cared for by the Hanson family as a child. He was all too ready to return the favour.

St George’s, Bloomsbury. The wedding party climbed the front steps on their arrival, but following the service made a hasty exit through the back door.

The aspiring John Hanson: could that be the grounds of Farleigh House through the window?

The Prince Regent and future George IV, representing the very worst of the upper classes.

A case of ‘spot the woman’ amid a sea of men: the trial of Queen Caroline in the House of Lords.

A physician for the great (and wealthy), Dr Matthew Baillie.

Did Portsmouth fit this caricature of madness? (The Lunatic by Thomas Rowlandson)

Or was Portsmouth more like the idiot depicted in Hogarth’s painting? The gormless servant who fetched laudanum for his suicidal mistress has no comprehension of his error.

‘I shall never part with this house’: Portsmouth’s heartfelt letter to his brother.