Ok...it is a slight cheat saying this is from Poland. I bought this card at the Art Institute of Chicago on my very first ever visit there. However, it is of an anonymous painting from Krakow featured in the art exhibit about Polish art and the winged hussars (ie: winged horsemen visible in the painting).
The painting's title: Entry of the Wedding Procession of Constance of Austria and Sigismund III into Cracow [Krakow]: The King's Hussar Regiment.
However, today is also Polish Constitution Day, commemorating the May 3, 1791 constitution of the Polish-Lithuanian Commonwealth. .It is often considered the oldest written constitution in Europe and the second oldest in the world behind that of the United States.