Among all the pupils of Rembrandt, only one had his first day in the master's studio recorded. In his description of the town of Leiden, Jan Jansz Orlers claims that Dou started his apprenticeship on 14 February 1628. It is thus ironic that Dou's progress as a pupil has not been traced in any known works, the more so given his subsequent breathtaking rise to fame. The task is admittedly challenging. There is no further documentation of his training, which lasted until 1631, and, of course, there are no signed and dated works from this period. Based on the close stylistic analysis of a substantial number of paintings hitherto considered the work of anonymous Rembrandt pupils of the Leiden period, conducted in the process of conservation treatment, the author proposes to identify a cohesive group of paintings as the product of Dou's period of study with Rembrandt.

Good quality anonymous paintings provoke academic curiosity. A case in point and of particular interest for the subject of this essay is Anna with the Blind Tobit in the National Gallery in London. From the late nineteenth century to present day, it has alternated between Rembrandt and Gerrit Dou. Today, many of the respective experts on both artists firmly reject it.