William Hogarth, artist, 1697 - 1764, sergeant painter to King George II lived on the east side of this square.
Site: Hogarth lost plaque (1 memorial)
W1, Leicester Square
Londonist posted this picture in 2013 and there we learn that Vanguard's founding Director, Mac McCullagh, has collected odd, and sometimes very large, objects over the 50 years of the company. This plaque was removed possibly in the 1980s and is held at Vanguard's self storage in Alperton Lane, Greenford. So, OK, it's not technically lost, but it's not where it belongs!