After a series of vain attempts to conquer Northern Italy, on 25 June 1183, Frederick I, Holy Roman Emperor, known as “Barbarossa”, granted autonomy to the 17 cities of the Lombard League, among them Modena. The Lombard League was a defensive alliance established in 1167 as a form of resistance by the cities of Veneto and Lombardy to imperial power. The aim was to defend or reconquer their own autonomy and put an end to war. The Peace of Constance saw the emperor granting some privileges to the cities, although reserving the right to approve the election of judges, consuls and podestà (imperial governors).