Focus on Claes Duyst van Voorhout and analyze the Provenance.
The painting is one of the best-documented paintings in Hals' oeuvre, first documented by Gustav Friedrich Waagen in his description of the paintings of the Lord Egremont in 1854. After that it was included by Wilhelm von Bode in 1883, by Ernst Wilhelm Moes in 1909, Hofstede de Groot in 1910, by W.R. Valentiner in 1923, Trivas in 1941 and by Gerrit David Gratama in 1946. Both Seymour Slive and Claus Grimm agree it is by Hals.
The MET lists various sale entries from Lord Egremont's time up to their acquisition date. In his 1989 catalog of the international Frans Hals exhibition, Slive included discussion of an old label on the back which listed the portrayed man as Claes Duyst van Voorhout, brewer in "De Zwaanschel". 20th-century archival research revealed that a Nicolaes Pietersz Duyst van Voorhout indeed was owner of the brewery called the "Swaenshals" (Swan's neck), who testified in Haarlem in 1629 that he was 29 years old, which fits the date for this portrait that was painted about 10 years later.
Wilhelm von Bode Hofstede de Groot Ernst Wilhelm Moes Seymour Slive Claus Grimm W.R. Valentiner Gerrit David Gratama Frans Hals Gustav Friedrich Waagen