Yes, this is true! I was young and wondering why my mother is dark skin and my dad is medium white. My sister is dark. My brother & I are very light.. We all have blue eyes and mom have brown eyes. I couldn't figures it out.
Finally I went to library to read book about Poland. Boy, this really changes my ideas and how things happens back then. I foung out Poland was under Austrian & Hungarians rules for so many years like 900 hundred years till 1930"s In Warsaw there were French peoples, Russian people, Sweden poeple, and some of others were building Warsaw.
I know you had Napoleon in Poland, he is Italian married Polish woman.
In Southern part of Poland Crawcow was ruled by Austrian & Hungrian Kings which mean German Settlers, Austrian Setter, Ukrain Settlers, Czech Setters and others. I heard Turkish people were in this area Tatra Mountain.
It is really long story, I advise all of you to read book Poland. You will get ideas.
I think I might be French, German, Austrian & Polish. Maybe Czeck.