Forced conversions have a history throughout Europe, but I was wondering whether there were many accounts of sincere conversions in Poland during this period. I have a personal interest in this, since my great-grandmother was Polish, and though obscure the details may be, seems to have converted to Catholicism from Judaism.
Additionally, she ended up in France during the German-occupation, so if anyone has details on Polish immigration to France in the 30’s, I’d be glad to hear.
Most of the evidence I have seen suggests that the answer is no, but that only tells a small part of the story. One reason few Jews converted to Catholicism, or any other Christian denomination, during Pilsudski’s rule is that many Jews had already converted in the 19th Century during the “Frankist” movement, which was a major push to convert Jews to Christianity and the ones that did not had been raised in an environment that was effective at deterring further conversions. Another reason is that Pilsudski did not seek to convert the Jews to Catholicism, but rather to assimilate Jews into mainstream Polish society. While the Catholic Church was important to Polish Nationalism, it was by no means always necessary for it, so he didn’t see Judaism as an inherent barrier to assimilation.
Pilsudski generally enjoyed support from Jewish leaders.
For what it’s worth, Poland has historically been one of the most religiously tolerant countries in the world.
I second what @klkevelson1 That conversion was part of a larger set of trends in Ashkenazi jewish demographic decline that was heavily complained about in the 1930s due to internal fracturing within the jewish community and the development of secular law, urbanization, and democracy.
No less than Arthur Ruppin kvetches about Vienna’s jewish population in 1936 by saying “Vienna Jewry is moving towards extinction.” And the reasons he was complaining (demographic data) were occurring all over Europe. Bernard Wasserstein’s “On the Eve” gets into this in detail. If nothing is forcing you to be jewish, then why be jewish - so people did all sorts of things instead, as well as experiment with new variations of Jewish identity (and they still do this, because the Jewish community has never resolved the issues raised by the Haskalah).