“No one in the entire period before the rise of Protestantism would have claimed to have been a Protestant since no such concept existed.”
Quite so, I don’t think the word “Protestantism” would have been used. Yet there were many reformers over the years, who protested heresies in the RC church, some successfully, some not so.
You wrote:
“Quite so, I don’t think the word “Protestantism” would have been used.”
Nor could it. And that proves my point.
“Yet there were many reformers over the years, who protested heresies in the RC church, some successfully, some not so.”
Untrue. There have never been any heresies taught by the Church for anyone to “reform”.