Unit: 200 zloty
When I started looking up information for this post I thought it was going to be just another currency bill, nothing special. But while searching for who it was on the obverse of this specimen I found out an interesting history behind this bill. I kept searching Google and was seeing that King Sigismund I (the Old) was on the Polish 200 Zloty bill. However it is quite clear that the guy on this bill is NOT Sigismund I. As it turns out this piece was made in 1988 which was part of the Third Zloty series which was from 1950 to 1990 where Poland actually didn't use the zloty. Instead it used a currency unit known as the zloty dewizowy which was a sort of foreign exchange bill. Apparently the zloty was not convertible for exchange and rates differed. But it was finally replaced with the current zloty after the fall of Communist rule.
Poland still uses the Fourth Zloty series, not the Euro....yet. The 200 zloty bill continues to have Sigismund I on it, and you can see what the other bills have (they come in 10, 20, 50, 100, and 200 zloty denominations) at thisPolish banknotes page. As for the Euro it seems unlikely that Poland will adopt it before 2019 as it would need to join the Eurozone. 60% of the nation oppose switching from the zloty to the euro so it seems unlikely that the country will adopt it anytime soon. There is still a ton of more interesting history of Poland, Jaroslaw Dabrowski, Polish euro and the Polish zloty that I didn't get a chance to go into, so I suggest going out and exploring the topics, like how zloty is based on the Polish word for gold which is why this currency has been used since the Middle Ages and being officially adopted in the 15th century.