> joined the Kingdom of Poland only seven years before his birth. > I'd say that calling him either German or Polish would be inappropriate. By the same logic

> joined the Kingdom of Poland only seven years before his birth. > I'd say that calling him either German or Polish would be inappropriate. By the same logic, for Thomas Jefferson, born 1743 in a British colony, it would be even more inappropriate to call him American, as that country didn't exist until 1776. What's true however is that, historically, the ideologies of current nation states didn't exist in 1473, and that some categorizations used today are really ahistorical. Still, people knew which language their ancestors and family spoke, and there is some information about that in Wikipedia regarding Copernicus. That's something that means something even to us today, where we could live in one country and mostly speak one language but still don't deny that our family speaks another, or that we don't speak the language of our ancestors. E.g. https://en.wikipedia.org/wiki/German_Americans https://en.wikipedia.org/wiki/German_Americans "With an estimated size of approximately 44 million in 2016, German Americans are the largest of the self-reported ancestry groups by the US Census Bureau in its American Community Survey."