On 2 February 1478, the Carinthian Peasants' League (German: Kärntner Bauernbund) was formed in the Ortenburg lands at Spittal an der Drau under the leadership of one Peter Wunderlich, raising some concern among the local nobility and clergy. Meanwhile, the Ottoman-Venetian War raged through the Isonzo valley in the south, where the Turks unsuccessfully besieged the fortress of Gradisca and then turned northwards into the Julian Alps. In May the farmers gathered at Villach where they organized a 3,000-strong army to face the invaders. They started obstructing the steep Predil Pass route, however, a 20,000-strong Turkish contingent of professional akinji cavalry were able to remove the barriers and to abseil their horses over rocky terrain.