One of only a handful of early portraits known to have been executed by him, it has been dated to c.1743 and will be estimated at £30,000-50,000 in an auction on March 23.
Art historian and Gainsborough specialist Hugh Belsey, who has assisted the auction house with the cataloguing, listed only two earlier portraits in his catalogue raisonné: the abovementioned self-portrait and a miniature portrait of a young girl.
This 14¼ x 9¾in (36 x 25cm) oil on canvas is thought to have been completed while the artist was lodging in Hatton Garden following his move from Suffolk to London, and is thought to depict a member of the Seton family, although no details about the sitter have thus far emerged.
The picture previously sold at Sotheby’s Colonnade in October 1995 as ‘Circle of Charles Phillips’ and at Woolley & Wallis in September 2015 as ‘Circle of Arthur Devis’. It was bought by Cheffins’ vendor at the latter sale for £2000.
Belsey said: “It is only in recent years that Gainsborough’s earliest portraits have been identified. The artist’s acute observation and his extraordinary ability to paint fabrics are tell-tale traits and this small portrait of a young woman from the Seton family is among the very earliest painted by Gainsborough.”