I believe it was the Edict of Worms that condemned Luther and the ism that followed his assertions. Europe was at the time in difficulty with the Ottomans, whose incredibly well United Empire had almost taken Vienna which is basically how an army gets from the flatter lands of Balkan Croatia into Western Europe, where in the 16th Century Princes were less troubled by the Ottoman than they were by each other. It was the Pope who said something like "If we don't pull ourselves together and unite, we'll be paying taxes to the Turks." One of the Protestant answers was something like "Until you recognize our ism we're not going to take much notice of anything you say, and the Ottomans might treat us better, they're far more understanding of religious differences than you lot appear to be!"
I forget which Pope it was, but good council prevailed. Charles V, a Spanish
Holy Roman Emperor who didn't much like the whole Protestant Idea or Germans for
that matter, called for a "Come to Jesus Moment" or a "Diet" in the Bavarian City of Augsburg. Representatives of both sides gathered, they dressed up and
the more northern Europeans agreed to stop doing things like calling the Pope an
antichrist, and the more southern Europeans agreed to at least vaguely admit
that Luther had a couple of good ideas. There are some who will argue that what
emerged from the discussion was the Protestant Church. There are two points.
First, nothing much changes. Second, Luther who at the time was an outlaw,
wasn't invited to the Diet of Augsburg, but during the Diet he was in Augsburg
writing pamphlets and being very well looked after by Carmelite Monks at Saint
Anne's Monastery. For those interested Saint Anne was Jesus' grandmother.