Edward Byng was the principal studio assistant of Sir Godfrey Kneller, initially employed about 1693 as a general assistant and then as drapery painter. By Kneller’s death in 1723 he was a close colleague, clearly held in high esteem, as he is mentioned in his will as having “for many years faithfully served me” and as lodging actually in Kneller’s house in Great Queen Street. He was also left an annuity of £100, an enormous sum for the time, and directed that he should complete unfinished pictures, for which he would receive remaining sums due. In addition to this he also inherited the valuable backlog of drawings in Kneller’s studio recording poses and postures from many of his paintings.

Byng’s identity as a draughtsman is defined entirely by studio copies after Kneller paintings. The British Museum owns a group of bound volumes containing a large number of similar drawings to that presented here, in addition to academic studies and life size tracings from the heads of Britsh portraits. Although a number of assistants were undoubtedly employed in producing copies, this particular type has generally been classified as the work of Edward Byng in conjunction with his brother Robert (c. 1668-1720) who was also an assistant to Kneller.

Lady Essex Mostyn (née Finch) was the daughter of Daniel Finch, 2nd Earl of Nottingham. She married the Welsh politician Sir Roger Mostyn, 3rd Bt. (1673-1739) with whom she had thirteen children. This drawing is a sketch by Byng of the original portrait painted by Kneller in 1705; it was published in reverse as a mezzotint by John Smith. Never intended as a finished portrait to hang on the wall, it was produced more as a record of a commission or model pose for future reference. Such drawings provide important information on the working methods of the large portrait studios of the early eighteenth century.

As well as the majority of Kneller’s studio drawings being held by the British Museum, the Yale Center for British Art, Paul Mellon Collection, U.S.A. has some very similar to the type presented here.