This unknown lady has traditionally been identified by family lore as Mary Dalison (1720 – 1751), daughter of Thomas Dalison (d.1751), and Jane Etherington (d.1722). However, the portrait clearly dates by style and costume to the 1670s, several generations earlier. The Dalisons, also spelt ‘Dallison’, were tangentially descended from Sir Roger Dallison MP, 1st Bt. Laughton (c.1562 – 1620), whose son Thomas Dallison, (painted by Paul Van Somer, also with The Weiss Gallery), was a captain of the Royalist army and a colonel of the horse under Prince Rupert’s forces, killed at the battle of Naseby in June 1645, having never sat in Parliament. Unmarried, he left an estate worth £12,000.
Our sitter wears her hair in fashionable ringlets and is attired in informal classical dress, a style made popular by Van Dyck and later, by Lely. This state of semi-déshabille allowed for a greater display of flesh. Her blue silk mantle is fastened with a diamond and she wears pearls to signify purity as well as wealth; these may have been a ‘stock’ design, chosen and painted in to add grandeur to a provincial sitter with aspirations.
The distinctive feigned cartouche was a popular format for bust-length portraits of this period, perhaps the greatest exponent of which was the female artist and copyist of Lely, Mary Beale. However, the distinctive modelling of our sitter’s face, with its defined contours and dramatic use of shading is particularly redolent of the Dutch émigré artist, Martinus van Grevenbroek. Van Grevenbroek, first recorded at The Hague in 1670 ‘aged 24’, is likely to have worked in London as a studio assistant for one of the fashionable portraitists working of the day, such as Sir Peter Lely (1618 – 1680) or John Riley (1646 – 1691), whose large and lucrative studios attracted accomplished young artists from the Netherlands seeking to expand their fortunes. Ellis Waterhouse also records that “Grevenbroek was presumably the ‘Mr Grevenbroek the Dutch painter’ who painted portraits for the Earl of Northampton in 1665 and 1666’”.
 Ellis Waterhouse, The Dictionary of 16th & 17th Century British Painters, pp.113-114.