This person is the subject of ongoing research. We have started by researching their relationship to the enslavement of people.
Charles William Howard, 7th Earl of Suffolk (1693–1722) owned an enslaved person, Scipio Africanus (1702–1720). (‘Scipio Africanus’, Wikipedia [online], <https://en.wikipedia.org/wiki/Scipio_Africanus_(slave)> accessed 5 August 2021.)
The Earl of Suffolk said a few words in support of the bill [Slave Trade Abolition Bill]' on 5 February 1807. (Parliamentary Debates: Official Report: ... Session of the ... Parliament of the United Kingdom of Great Britain and Ireland, vol. 8, 1812, col. 672.)
National Gallery painting connections
Former owner: NG purchased from Howard in 1880: NG1093.
History of Parliament Trust (ed.), The History of Parliament: British Political, Social & Local History, London 1964-, https://www.historyofparliamentonline.org/
Checked and not found — Item on publisher's website