could have been German?
He could have been German or Polish or Czech or Wendish or Jewish or most anything else. We cannot know. Let me take it from the beginning. The German name Bernhard evolved as a compound name comprising Old High German bero (bear) and hart (strong) and originally meant somethign like "strong as a bear". It eventually went into different languages as Bernard (English, French), Bernardo (Italian, Spanish, Portuguese) and Bernat (Hungarian, Czech, Polish). Let's say a German named Bernhard moved to Poland in 1100 or 1300 AD and settled. Soon local Poles would have started calling him Bernat and when he fathered a son: presto -- instant Bernatowicz. Regardless of whom Bernat had married, baby Bernatowicz would be at least 50% German. It depends on whom Bernatowicz and his descendnats intermarried with over the centuries as to what percentage of which nationality his DNA now comprises. A DNA test can determine that.
Bernat is no exception. Lets take Thaddeus (Polish Tadeusz) which I presume is your first name. It goes back even further to Aramaic (Jesus' language) where it had the form of Thadday. It was rendered in ancient Greek as Thaddaios and eventually went into different languages as Thaddé (French), Thaddäus (German), Tadeusz (Polish), Tadeáš (Czech) and Thaddeus (English). But that does not mean you trace your roots to Palestine where Aramaic was once spoken or Ancient Greece.
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