‘I’m not paying,’ Ginie would laugh, ‘my dog wouldn’t hurt anybody, they should have fought him for it.’

But Caesar was enormous and most people were afraid of him. One day, he fell asleep on the tram tracks and held up traffic for half an hour, until some brave soul gave him a nudge with his boot and told him to run along home.

While on a summer holiday in Canada, Lil Courtauld fell down some steps and developed an agonizing pain in her side. But when she had an exploratory operation on her return to London, it revealed the existence of several large tumours. Her doctors admitted that there was nothing they could do for her, except attempt to make her as comfortable as possible.

Sam tried to hide the news from everyone, but Stephen guessed from her wasted appearance and the pain she couldn’t hide, that something was dreadfully wrong. Though Lil bore it with courage and stoicism, the end came with shocking speed and she passed away on Christmas Day. It was a great blow to Stephen, who was fond of his sister-in-law, despite the cold reception she had given Ginie.

Sam was devastated and though his public work and benefactions continued, he virtually stopped collecting art and became increasingly introspective. He spent more time at his country house at Gatcombe Park and began to write, embarking on a painful search for self-knowledge and spirituality through poems, essays and autobiographical snippets, some of which he shared with Stephen.

With these changes in the family, Eltham Palace became a gathering place for the Courtauld clan, as well as for London society. Divorce was becoming increasingly acceptable in all circles. Moreover, Stephen’s wealth and philanthropy, combined with Eltham’s splendour, more than compensated for Ginie’s unconventional behaviour. They became known as one of London’s most glamorous couples, renowned for their stylish and extravagant entertaining.

Some months after they settled in, they hosted a ball in the great hall with a fireworks display on the grounds. Eltham bustled with activity for days beforehand: a small army of servants arrived to clean and dust and polish each room until it sparkled, enormous bouquets of lilies and orchids from the greenhouses were carried into the house, fires were lit in every hearth.

On the evening of the party, Ginie was applying makeup at the dressing table in her bathroom: a sumptuous space, with onyx-lined walls and a marble bath set in a Byzantine recess of gold mosaic. Caesar was leaning his big head on her thigh. The other dogs lay on the floor, a sharp, earthy smell from the garden clinging to their fur. The quacking of ducks from the moat sounded loudly.

Stephen knocked on her door, handsome in his dinner jacket. Without saying anything, he handed her a gift-wrapped box from Cartier. She tore off the dark red ribbons, inside were two brooches in gold, decorated with diamond and enamel.