In 1900, the Welsh Industrial Association held an exhibition at 83 Eaton Square, rented by the Winifred, Countess of Dundonald, the event was visited by Alexandra, Princess of Wales.
The person presiding over the refreshment room exhibition was Kathleen, Duchess of Wellington, assisted by Mrs A. J.
Warden, with a party of attractive ladies wearing the national costume of Wales accompanied by Ivor and Albertina Herbert of Llanover's Harpist playing for the occasion.
The aftermath of that war saw most of those converted to commercial and institutional uses, leaving the square almost wholly residential, raising its prominence.
Some of the houses remain undivided but many have been internally converted into flats or multi-storey instances (maisonettes) by permission or instruction of the Grosvenor Estate.
Between 1940 and 1944 the Belgian government in exile occupied its three numbers which have been long used as that country's embassy in Britain and further premises in central London as their lesser homes and offices.
The Bellamy family of Upstairs, Downstairs lived in "165" Eaton Place, one of the grand approach ways.