 Burgundy declared war on Habsburg in 1287, and Rudolf of Habsburg treated Bern as a Burgundian city, laying siege to it twice without success.The son of Rudolf of Habsubrg, duke Rudolf of Swabia moved towards Bern with 300 cavalry in April 1289 and prepared an ambush outside of the city while harassing the landscape in an attempt to draw out a sortie.The plan worked, and the Bernese were surrounded and defeated outside the gates of their city.