In 1291 the three forest cantons of Uri, Schwyz and Unterwalden signed the Federal Charter uniting them in their struggle against Habsburg rule. The defeat of the Habsburg army made it possible to secure the existence of the Swiss Confederation within the Holy Roman Empire. By 1353 the "Old Confederacy" of eight states had been formed. This and the further development of the confederation made it more powerful and wealthy. In 1515 the Swiss defeat in the Battle of Marignano put an end to the so-called "heroic" epoch of Swiss history. The Reformation initiated by Zwingli led to the conflicts between some cantons. Such were the early stages of development of the confederation. It went through many hardships and many historical events took place here before it became what it is now, the Switzerland of today.