Roy Precious - Antiques & Fine Art has dated this piece to the 18th Century.
The British Palladian or 'Kent' frame, with its distinctive outset corners, is called after the architect and designer William Kent (1685-1748); he derived it from the late Mannerist work of Michelangelo, interpreted by Palladio and Inigo Jones.
The painting and its frame were completely integrated with the overall setting. The 'Kent' frame was decorated with strong classical mouldings, such as egg-&-dart, ribbon-&-stave and Greek fret.

This lovely portrait is a head and shoulders version of a large three quarter length of Mary, painted by Sir Godfrey Kneller for Queen Mary II for her collection known as The Hampton Court Beauties.
LADY MARY COMPTON, later MARY SACKVILLE, COUNTESS OF DORSET (1669-1691)was Lady of the Bedchamber to the Queen.

Her father was James Compton, 3rd Earl of Northampton (1622-1681), and her mother was the Hon. Mary Noel (died 1719). In 1685 the sitter married Charles Sackville, 6th Earl of Dorset (1637-1705) KG. They lived at Compt Hall, Waltham Abbey. The union produced two children, Linel Cranfield Sackville, 7th Earl of Dorset, (created Duke of Dorset in in 1720), and Lady Mary Sackville, died 1705, first wife of Henry Somerset, 2nd Duke of Beaufort.

Mary, Countess of Dorset died of smallpox in 1691 aged 22 years.
SIR GODFREY KNELLER (1646-1723) was the most distinguished painter of baroque portraits in England.
Born in Lubeck, he trained with Bol and Rembrandt, coming to London in 1676.

By 1679 he had painted the King and remained the most famous and successful portrait painter in England until his death.
In 1688 he was made Principal Painter to the King and was knighted in 1692 and a made a baronet in 1715.
SIZE:32.75 x 28 inches inc. frame.
PROVENANCE: Old Nottinghamshire Private Collection.
Roy Precious - Antiques & Fine Art has dated this piece to the 18th Century.
Roy and nadine precious: specialists in portraiture from the 16th to the 20th century. Established in 1972.
You can view the stock and full dealer information on the Roy Precious - Antiques & Fine Art Profile Page