One of the many pernicious acts of destruction committed by the Nazis against Britain in the Second World War was the burning of Holland House by incendiary bombs in September 1940. Bits of it remain, and the 52-acre park and gardens are still there, but it takes a strong act of imagination to recreate the physical setting for arguably the most celebrated political and literary salon in English history.

The house itself, a jumbled labyrinth dating from the Jacobean period, was no great architectural beauty. But from its restoration by Henry, third Baron Holland, in the 1790s to his death in 1840, it was the centre of Whig activity. It was not, strictly speaking, a salon, a disagreeable French invention in which you were expected to sparkle for three hours with no more sustenance than a glass of sweet vermouth and stale petits fours. At Holland House, by contrast, you were invited to ‘dine, and bring your nightcap’. The food was ample and often delicious, Lady Holland paying the cook a sumptuous 110 guineas a year, and the accommodation spacious. But you did not need to stay. The gardens opened onto what is now Kensington High Street, and Mayfair and Westminster were only a cab ride away.

Linda Kelly has written a delightful book about this unique phenomenon during a crucial period of English history. She does not bother us too much about the house itself but concentrates on the people who glorified it and became known as the Holland House Set. Charles James Fox dominated its first period. Subsequent members included Earl Grey, Palmerston, Macaulay, Lord John Russell and Melbourne. Sheridan was a habitué until his death, taking up to bed with him a book from the 10,000-volume library and a bottle of wine. The wits were led by Sydney Smith, Samuel Rogers and Talleyrand, the celebrities by Byron and Madame de Staël.

There was a memorable visit in 1828 by Sir Walter Scott, who left a fine description in his journal:

The freshness of the air, the singing of the birds, the beautiful aspect of nature, the size of the venerable trees, all gave me a delightful feeling … It seemed there was pleasure even in living and breathing, without anything else. We (ie Rogers and I) wandered into a green lane bordered with fine trees, which might have been twenty miles from town. It will be a great pity when this ancient house must come down and give way to brickworks and brick-houses. It is not that Holland House is fine as a building; on the contrary it has a tumbledown look; and although decorated with the bastard Gothic of James I’s time, the front is heavy. But it resembles many respectable matrons, who having been ugly during youth, acquire by age a look of dignity – though one is chiefly affected by the air of deep seclusion round the domain.

Others who wrote of the place were Thomas Creevey and Charles Greville. The latter referred to the ‘social despotism of this strange house’, reflecting the character of Lady Holland, and added:

Though everyone who goes there finds something to dislike or ridicule in the mistress of the house, or its ways, all continue to go; all like it more or less; and whenever by the death of either, it shall come to an end, a vacuum will be made in society which nothing will supply. It is the house of all Europe; the world will suffer by its loss; and it may with truth be said that it will eclipse the gaiety of nations.

Lady Holland was a divorcée (Lord Holland was her second husband) and could not be received at court. This was the main reason for her entertaining – and none could resist coming to her. She felt the prohibition bitterly, though, not least under young Queen Victoria, who enforced the rule strictly. But the ban rebounded because it deprived Victoria occasionally of Melbourne, whom she adored. He insisted on going to call on Lord Holland at Holland House, even when staying at Windsor. The queen confided in her journal:

 ‘Must you really?’ said I, much vexed; ‘I want to dine at Holland House; it’s as well to hear what he has got to say; I’ll come back Sunday’, he replied. ‘You must’, I said. I was selfish enough to be quite cross inwardly at this announcement … I said I dreaded Lord and Lady Holland’s return, as I knew she would get hold of him; and that Holland House was a great attraction, and that I was jealous of it.

Lady Holland figures largely on these pages. But the hero of the book is, quite rightly, Lord Holland himself. Under Kelly’s skilful and well-judged treatment he emerges, for the first time, as an important figure in English history, albeit an unobtrusive and deliberately self-effacing one. He was a key power behind Catholic emancipation, the fight against slavery and the survival of Whig principles, finally vindicated in the Great Reform Act. His knowledge of foreign affairs, especially in Spain, was profound. He had a genius for conciliation, and a genuine love of humanity in general and of people in particular. He had minor private bickerings with his wife but no one ever saw him out of temper. No wonder everyone loved him – even the Duke of Wellington. It was precisely the combination of beautiful, sharp-tongued mistress and omnibenevolent, sweet-natured master that gave Holland House its irresistible allure to such an astonishing galaxy of talents. Linda Kelly brings all this out gracefully in her hugely readable book.