Changes

Furthermore, Calvinists, because they were recognized under the Peace of Augsburg, were in effect unable to secure any tolerance for their faith in the Empire. This was to play an important part in the breakdown of the Augsburg Settlement. Indeed, the collapse of the Augsburg settlement can be attributed to actions borne out of Calvinists' frustrations. The so-called ‘defenestration of Prague’ involved Calvinists attacking and throwing the Holy Roman Emperor's representatives out a window. This was to trigger the Thirty Years War that left most of central Europe a wasteland.<ref> Wilson, Peter, <i>The Thirty Years War: Europe's Tragedy</i>. London: Belknap Press, 2011), p. 67</ref>

In the Holy Roman Empire, there were very many ecclesiastical principalities. They ranged in size from a small town to large territories, often containing significant urban centers such as Cologne. The Treaty, after protracted negotiations, had to deal with the issue of ecclesiastics who converted to Lutheranism. The Catholic side was concerned that a bishop or another religious leader converted that his realm would become Lutheran. This had happened during the Reformation. The Head of the Teutonic Knights in Prussia, originally an order of warrior-monks, had converted to Protestantism, and as a result, all the Prussian territories had become Protestant. The Catholics demanded that any bishop or religious leader that had converted to Lutheranism should return his realm as by rights their lands belonged to the Catholic Church.