Imperial ban
The efforts of Emperor Frederick II to gain greater power in Italy were aborted by the cities, which earned the League an Imperial ban. The emperor's measures included the taking of Vicenza and his victory in the 1237 Battle of Cortenuova which established the reputation of the emperor as a skillful strategist. Nevertheless, he misjudged his strength, rejecting all Milanese peace overtures and insisting on unconditional surrender. It was a moment of grave historic importance, when Frederick's hatred coloured his judgment and blocked all possibilities of a peaceful settlement. Milan and five other cities withstood his attacks, and in October 1238 he had to unsuccessfully raise the siege of Brescia.