We are grateful to Professor Albert Blankert (written communication, 4 August 2003), who from a transparency and black and white photograph confirms the attribution to Ferdinand Bol. Professor Blankert makes reference to several details in other portraits by Bol that confirm his assessment (see A. Blankert, Ferdinand Bol, Doornspijk, 1982, nos. 159-60, 173, pl. 170-1, and 185).
In the previous sale catalogue, Professor Werner Sumowski identified the above painting as a work by Ferdinand Bol and dated it to the late 1660s. He compared it to a portrait of a woman by Bol signed and dated 1667 at the Musée des Beaux-Arts, Quimper (see W. Sumowski, Gemälde der Rembrandt-Schüler, VI, 1983, pp. 3086 and 3152, no. 2022).
Bol was born in Dordrecht and may have studied there with Jacob Gerritsz. Cuyp. He moved to Amsterdam and entered the studio of Rembrandt at the age of about twenty and was therefore probably more of an assistant than a pupil to the master. He left Rembrandt's studio in around 1637 and his earliest independent works, especially his portraits, show the strong influence of Rembrandt. Subsequently his portraiture takes on a more refined style, as in the above portrait and is closer to the more fashionable manner of Bartholomeus van der Helst.