In 1480, Heinrich von Gundelfingen collected a number of local legends into a book called the "Herkommen der Schwyzer und Oberhasler" (Traditions of the Schwyzer and Oberhasler) which claimed that the land had been settled by 6,000 Swedes and 1,200 East Frisians after they rescued the Pope from a barbarian attack in 400 AD. The central elements of the myth, the Swedish origin and the rescue of the Pope became central elements in the Schwyzer state mythos. By 1531, this special relationship to the Catholic faith and the Pope was specifically mentioned in a resolution that passed in the Landsgemeinde. This resolution was passed against the backdrop of the Protestant Reformation and the tensions following the First War of Kappel two years earlier. Soon thereafter, the Catholic cantons refused to help the Three Leagues ("Drei Bünde") in Graubünden in the Musso war against the Duchy of Milan, Zürich promptly considered this a breach of contracts between the confederacy and the Three Leagues and declared an embargo against the five alpine Catholic cantons, in which Bern also participated. While the "Tagsatzung" had successfully mediated in 1529, on this occasion the attempt failed, not least because the reformation leader Huldrych Zwingli was eager for a military confrontation. The Catholic cantons declared war on Zürich on 9 October 1531. On 11 October 1531, Schwyz, Uri and Zug decisively defeated the army of Zwingli. Hundreds of soldiers were killed, including Zwingli himself. Schwyz remained staunchly Catholic following the war.