Sir Henry Petty Fizmaurice, 3rd Marquess of Lansdowne (1780-1863) was "a very moderate" Whig politician. Elected MP for Calne in 1803, he became Chancellor of the Exchequer under the 1st Baron Grenville in 1806, and after the fall of Grenville's ministry became an active leader of the opposition. He succeeded his brother as marquess in 1809. For the next twenty years he supported many liberal measures, such as the abolition of the slave trade. Under Lord John Russell he served as president of the council (1846-52), and remained in the cabinet, without office from 1852-63. Lansdowne was a francophile, and an enterprising though somewhat parsimonious art-collector. One of the first British patrons of Henry de Triqueti, he had purchased from him a marble low relief of  the Virgin and Child in 1838.

My identification of this bust is based upon a comparison with other portraits of the marquess, in particular the bust on the memorial to him in Westminster Abbey, by Joseph Edgar Boehm.

The Morning Post of 11 May 1854 carried an advertisement, which ran as follows: "The Marquis of Lansdowne KG. The Baron Marochetti having executed a bust in bronze of the above respected nobleman, Messrs Paul and Dominic Colnaghi and Co. beg to announce that they have made arrangement to publish it. The bust may be seen, and subscribers' names received for it at 13 and 14 Pall Mall East". Its small dimensions and format are similar to a number of miniature bronze busts by Marochetti offered by the firm of Colnaghi.