The mysterious, romantic figure of the young rider caused more controversy than any other Rembrandt painting, whose controversial authorship is just one of the ambiguities associated with this work.
A hat and a caftan trimmed with fur seem Eastern European, but perhaps this is just another excursion into theatrical masquerade. If so, then the picture is related to Poland not according to the plot, but only because it was subsequently acquired by the Poles.
On the other hand, an intriguing fact: in 1654 in Amsterdam, a pamphlet was printed under the name “Polish Horseman” in defense of the radical sect of socianians. There is much evidence that Rembrandt sometimes sympathized with sectarianism. Another mystery: a very unconvincingly depicted horse. It can be resolved by attributing the authorship of the picture to some student of Rembrandt, for example, William Drost. This was what the Commission of the Program decided, but its research brought on fire of criticism and in 1993 the Program stopped its work.
The Man in the Golden Helmet by Rembrandt Harmens Van Rhine 
Scholarly Dispute by Rembrandt Harmens Van Rhine 
Winter Landscape by Rembrandt Harmens Van Rhine 
Susanna and the Elders by Rembrandt Harmens Van Rhine 
Portrait of an Old Warrior by Rembrandt Harmens Van Rhine 
Portrait of a Scientist by Rembrandt Harmens Van Rhine 
Noble Slav by Rembrandt Harmens Van Rhine 
Speech of the rifle company by Rembrandt Harmens Van Rhine