[Old Sarge]

one of the most important, influential and regrettable events in Church history: the Protestant Reformation, or the Protestant Rebellion, as some prefer to call it.

Or the Lutheran Heresy.

[matthewrobertolson]

That, too. :)

[Cronos]

As a Catholic, I don’t find Lutheranism to be a heresy - and that’s acknowledged by the Church. Schismatic yes, but not heretic. There are non-catholic groups that broke off from Lutheranism that have ventured into heresy, but Lutheranism, no.