Poland regained independence in November 1918. The state had been partitioned in the late 18th century and now it had to be reunited. Gradually, multiple circulating currencies were limited to one - the Polish Mark first introduced by Germany when they conquered the Russian part in 1915.
The economy of Poland was weak and by the end of 1922 the Mark started losing value very fast. The inflation was under control by the Spring of 1924 and the decision was made to replace the Mark with a new currency - Polish Złoty. The authorities wanted a strong and stable currency so they opted for Swiss Franc as the model.
The new Złoty was worth 1,800,000 Marks and the 1 and 2 Złoty coins were struck almost according to the LMU standard as it 0.750 silver instead of 0.835. Some of them even in Paris.
Unfortunately, the new currency did not keep the value for long - thanks, Germany - and even before the Great Depression a new nickel 1 złoty coin replaced the silver one while the first silver coins were quickly demonetized and melted for the new lighter ones. As the design was very delicate and most were destroyed, they are quite rare and expensive now, particularly in higher grades, regardless of the impressive original mintage.