The History of the Building
20 Cavendish Square has a rich and interesting history running back almost 300 years.
Georgian Architecture & Historic Features
From its origins as a Georgian townhouse on one of London’s most ambitious estates, through the tenure of a Prime Minister, to its life today as the home of the Royal College of Nursing, this building has a wonderful London heritage.
The sense of history is immediate. It’s in the proportions of the rooms, the weight of the original oak doors, and the light flooding through the tall windows.
The Painted Staircase
The painted staircase is a work of art that has been here since the 1730s.
The murals are attributed, by the late Edward Croft-Murray, Keeper of Prints and Drawings at the British Museum, to three of Georgian England’s most distinguished decorative painters: Devoto, Thornhill, and Kent. There aren’t many conference venues where the backdrop has been appraised by the British Museum.
The main staircase walls carry large sweeping scenes of classical Rome, attributed to John Devoto, principal scene painter at Drury Lane Theatre. On the landing below, grisaille figures of the Arts and of Music are more in the style of Sir James Thornhill, one of the most prominent mural painters of his generation, who painted the dome of St Paul’s Cathedral and the Painted Hall at the Old Royal Naval College. The ceiling is a true masterpiece, painted in the manner of William Kent, with gilded hatching and grisaille caryatids supporting a trompe-l’oeil dome that opens to the sky.
The Period Features
The Ionic pilasters, sunk elegantly at the corners, have been associated by architectural historians with the hand of James Gibbs, who was working just around the corner on Henrietta Street when the house was built, and who went on to design St Martin-in-the-Fields and the Radcliffe Camera.
What you see from the square today isn’t quite what it appears. In 1932–34, architect Edwin Cooper stripped back the exterior, refaced the entire building in Portland stone, and added a full storey on top, all without disturbing the Georgian interiors within. The result is a feat of early twentieth-century engineering that looks like it’s been there since 1729.
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The Original Square and The House: 1717 to 1729
In 1717, Edward Harley, 2nd Earl of Oxford, began laying out one of London’s grandest new residential estates on his wife Henrietta Cavendish Holles’s landholding. The garden at the centre of the square was designed by Charles Bridgeman, who became gardener to the royal household.
No. 20 is thought to have been built between 1727 and 1729 by George Greaves, a Clerkenwell carpenter. Its first resident, Francis Shepheard, was a wine trader, East India merchant, and well-connected Harleyite politician, a man who understood the power of the right room in the right postcode. Nearly 300 years later, that hasn’t changed.
The Cowdray Club dining room
The Memorial Hall
Georgian and Victorian Life: 1755 to 1894
The house changed hands several times through the mid-eighteenth century. Its longest and most characterful occupancy began in 1755, when William Wildman Barrington, 2nd Viscount Barrington, moved in upon his appointment as Secretary at War. Under Barrington, the house became known for its parties, a reputation that outlasted his role in government. Some rooms just have a habit of bringing people together. Look closely at the marble fireplace in the Council Room and you’ll still find the double-headed eagles from his coat of arms.
The square itself attracted distinguished company. Princess Amelia, daughter of George II, lived at No. 16, and Captain Nelson at No. 5 in 1787. This has always been one of those addresses where London’s most influential people chose to be.
The Asquiths: 1894 to 1920
In 1894, Sir Charles Tennant bought No. 20 as a wedding present for his daughter Margot and her new husband, the Liberal politician Herbert Henry Asquith.
Margot was one of the most formidable political hostesses of her generation, making 20 Cavendish Square a key venue for London high society. She was a central figure in The Souls, the intellectual circle that gathered the sharpest minds in late Victorian and Edwardian public life.
When Asquith became Chancellor of the Exchequer, Margot declined to move to 11 Downing Street. When he became Prime Minister in 1908, she declined again. She preferred 20 Cavendish Square.
When the Asquiths finally left in 1920, the house came onto the market, advertised as suitable for “a nobleman, embassy or family of distinction.” What happened next defined the building’s character for the next century.
Lady Cowdray: 1860 to 1932
Annie Pearson, Viscountess Cowdray, was not a woman who did things quietly, and 20 Cavendish Square is proof of that. Lady Cowdray answered that advertisement, though not for the reasons anyone might have expected.
Born Annie Cass in Bradford in 1860, she became one of the most consequential philanthropists in the history of British nursing. Nicknamed the Fairy Godmother of Nursing, she was a suffragist, a political figure of considerable standing, and in 1932 was made a Dame Grand Cross of the Order of the British Empire. But her most lasting act was simpler: she saw the potential of this building, bought it, and gave it away to the nursing profession, for good.
The defining years
Lady Cowdray saw an opportunity to give the nursing profession a home worthy of it. It was Rachel Cox-Davies, matron of the Royal Free Hospital, who made it happen. Sharing a taxi with Lady Cowdray, she made her case: here was a building worthy of the nursing profession, in exactly the right part of London, and unlikely to stay available long. By the time they reached their destination, Lady Cowdray had heard enough. She purchased No. 20 outright from the Asquith family for £20,000 and, in 1922, gifted the freehold to the RCN.
She commissioned Sir Edwin Cooper to convert the townhouse into the Cowdray Club. Between 1922 and 1926 she funded the demolition and rebuilding of 1 Henrietta Place at the rear, adding the Great Hall, the Library, and administrative offices. Lady Cowdray laid the foundation stone in June 1922. Queen Mary opened the completed building in May 1926.
By the late 1920s the College had acquired No. 21, the corner house at the junction with Henrietta Place. In 1932 Cooper began the final and most ambitious phase: No. 21 demolished and rebuilt, No. 20 raised by an entire storey and refaced in Portland stone, with bridging steelwork suspending the new top floor and façade above the fragile Georgian fabric below. The painted staircase, the panelled rooms, and the original interiors were all preserved untouched within the 1930s shell. Work completed in 1934: a single, unified classical façade wrapping the corner of the square, with the eighteenth-century townhouse hidden inside.
The Cowdray Club: 1922 to 197
Formerly the Nation’s Nurses and Professional Women’s Club, the Cowdray Club set out to give professional women the same social advantages men enjoyed in London’s Clubland.
At its peak it was highly successful, with over 3,000 members. By design, 55% were nurses, 35% other professional women, and 10% “suitable women” from other backgrounds. Notable members included aviator Amy Johnson, ballet pioneer Dame Ninette de Valois, barrister and judge Rose Heilbron, Liberal politician Lady Violet Bonham Carter, and crime novelist Josephine Tey.
The Club closed in 1974, merging with the Naval and Military Club. The social and professional world it was built to challenge had changed.
The Royal College of Nursing
The Royal College of Nursing was founded in 1916 with 34 members, by the end of its first year, that number had reached 2,553. A Royal Charter followed in 1928; Queen Mary became patron the same year.
The “Royal” prefix was granted by George VI in 1939, following years of opposition from rival nursing organisations. Queen Elizabeth II served as patron for nearly 70 years, from her coronation in 1953 until her death in 2022. King Charles III is the current patron.
The Building Today
By the turn of the 21st century, the building risked becoming outdated for a modern organisation. Between 2000 and 2001, 20 Cavendish Square underwent a major refurbishment, upgrading a historic building to professional standards while preserving its character.
Office spaces, meeting rooms, and event spaces were overhauled. Cowdray Hall was enhanced for large-scale events, lectures, and corporate use. New heating, ventilation, and AV infrastructure brought the building up to modern compliance. The result: a fully functioning contemporary venue, with 300 years of history still written into its walls.
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