In the mid to late 19th century, it was frequently let, as a whole, to families of very high wealth or income, such as Lord Rosebery and Hannah de Rothschild of Mentmore Towers from 1878 to 1890.

Landsdowne's heirs sold the property in 1929, two years after the death of the 5th Marquess, a prominent government frontbencher (cabinet minister).

[3][4] Notable guests have included Benjamin Franklin, Oscar Wilde, Henry James, and the Comte de Mirabeau, among others.

[2] It co-serves as an address of Fitzmaurice House Ltd, the International Wine and Food Society which may meet here and The Junior League of London.

This conservation guaranteed for Devonshire House on Piccadilly open aspects (greenery-covered land save for discreet fences/railings) up to and including all of Berkeley Square.

[8] Prime Minister Liz Truss called the agreement "a resounding vote of confidence in the United Kingdom as Europe’s leading financial centre."

Owner, resident:- Tenants:- In the 1930s, the Metropolitan Borough of Westminster Council decided to build a road from Berkeley Square to Curzon Street, which required the demolition of all the garden front rooms of Lansdowne House.