That same man from this country holds a war hammer and guides his (*) white horse past a mountainous fortress in a painting made circa 1655.  
W. R. Valentiner asserted that a painting of a man from this country was actually of the Dutch hero, Gysbrecht van Amstel.  In a portrait by the same artist at the National Gallery of Art, a mustachioed man from this country wears a pearl earring and holds a gold-tipped baton in his right hand.  The Frick owns a painting of a man from this country in red pants and equipped with a quiver of arrows that may have been modeled on the artist's son, Titus.  That same man from this country holds a war hammer and guides his (*) white horse past a mountainous fortress in a painting made circa 1655.  A history painter from this country depicted the title nobleman ripping off his shirt in despair in 1866's Rejtan and also painted Skarga's Sermon.  Rembrandt painted a "nobleman" and a "rider" from the country, the latter of whom was a member of the Lisowski corps.  For 10 points, name this birthplace of Jan Matejko.
W. R. Valentiner asserted that a painting of a man from this country was actually of the Dutch hero, Gysbrecht van Amstel.  
Poland [or Polish-Lithuanian Commonwealth] 