Bonham's has these lot notes for the overall portrait, "The present work depicts The Hon. Aubrey Beauclerk (1740-1802), later 5th Duke of St. Albans, and his family including his eldest son Aubrey (1765-1815, later 6th Duke of St. Albans), who joined his parents in Rome in May 1778, and their two eldest daughters, Catherine (d. 1803) and Caroline (d. 1838).
On 4th June 1778, Lady Mary Lowther noted in a letter to Lady Mary Coke that 'Mr Beauclerk, Lady Catherine and Mr Brand were gone together abroad, being so in debt they found it troublesome staying at home'. Their trip abroad may have been arranged to try to escape the rumours of an affair between Lady Catherine and Thomas Brand. The Beauclerks spent almost three years in Rome during which time Smuglevicz painted them twice. One of these portraits is the present work, which depicts the family before the Castel Gandolfo where they rented apartments for the summer of 1779. The other portrait (now in Cheltenham Art Gallery) shows the family in the Roman campagna with an aqueduct in the background.
The attribution of the present painting to Smuglevicz was first suggested by Francis Russell in his Burlington Magazine article in 1978. His attribution was in turn based on that established by Brinsley Ford for his Portrait of James Byres and his family and also for that of the Portrait of James Byres and his family in an interior now in the Scottish National Portrait Gallery, Edinburgh. The present painting compares very well with these two works both in the distinctive, subdued palette and in the meticulous treatment of the drapery, particularly that of Lady Catherine's dress."