They depict the Antwerp widow Madame Guyot (Françoise-Jacqueline Peeters D’Aertselaer) and her eight children, a prominent family who lived near Brasschaet. The first of the portraits showed her with four of her children and the second featured the rest.
The paintings descended through the generations of the sitters’ family at the Château de Mishaegen before they sold at Sotheby’s in 1998. They had since been owned by Northamptonshire dealer Windsor House Antiques.
The 3ft 7in x 4ft 5in (1.08 x 1.34m) are both signed and dated 1792 and will be offered together with an estimate of £15,000-25,000.