Last month, Elizabeth at the Polish Genealogy Project, had a wonderful series on the history of Polish currency. I was fascinated with the samples and information she came up with. Her 3-part series can be found here, here, and here.
Poland was partitioned for many years and Elizabeth has examples of the currency from each of the partitions over time. This is a great resource for anyone writing up the family history of their Polish ancestors. Take a look and see which currency your ancestors used. Here's just one example, a 4 złoty note from 1794.