Well, there existed both nations and nation-states, fighting other nation states (often with conscious national sentiment and pride, like any modern era nation).
It was not all some blur, just because they didn't have modernity-style institutions.
It was not all some blur, just because they didn't have modernity-style institutions.
It's hard to understand that from our perspective, but bringing the current notion of a nation or a nation state into 16th century is an anachronism.