The sitter was the daughter of John Chester of Covent Garden and his wife Elizabeth, daughter and co-heir of Sir William Chester 5th Bt. Her grandmother was the daughter of George Hewett of Stretton Hall, Leicestershire, and Dorothea inherited the substantial Hewett estates, as well as property from the Chester family of Chicheley and from William Wood of Loudham Hall, Suffolk. On 2nd December 1764 she married Sir George Robinson, 5th Bt. of Cranford Hall near Kettering, owner of substantial estates in Northamptonshire, inherited in 1765 from his father Sir John Robinson. Sir George was high Sheriff of Northamptonshire from 1766-1767 and Member of Parliament for Northampton from 1774-1780. The Public Ledger described him as 'an honest, independent country gentleman of Whig principles and inclined to Opposition'. They had seven sons and two daughters, and their eldest son George succeeded to the baronetcy in 1815.
This beautiful portrait was painted in 1786, a year in which Romney painted several of his finest portraits of Emma Hamilton. Five sittings are recorded in February 1786 and Romney painted her husband in the same year.