Henry Dawkins (1728 - 1814) was MP for Southampton. Judging from the apparent age of the sitter, this pastel portrait dates from about 1750. The sitter was identified as Henry Dawkins when the portrait was sold by the Dawkins family in 1913. This identification may be confirmed by the label on the reverse, although this could simply refer to ownership.
The National Gallery, Trafalgar Square, London WC2N 5DN