I want to know the answer to the following question:
Which Battle was the first to interrupt the seeming invincibility of the Old Swiss Confederacy in 1515?
All the background I'm provided with is that "The Old Swiss Confederacy had acquired a reputation of invincibility during these earlier wars, but expansion of the federation suffered a setback in 1515 with the Swiss defeat in the Battle of Marignano.". Is that enough to answer the question?