The Lombard League was an alliance formed around 1167, which at its apex included most of the cities of northern Italy (although its membership changed in time), including, among others, Milan, Piacenza, Cremona, Mantua, Bergamo, Brescia, Bologna, Padua, Treviso, Vicenza, Venice, Verona, Lodi, and Parma, and even some lords, such as the Marquis Malaspina and Ezzelino da Romano. The League was formed to counter the Holy Roman Empire's Frederick I, who was attempting to assert Imperial influence over Italy. Frederick claimed direct Imperial control over Italy at the Diet of Roncaglia (1158). The League had the support of Pope Alexander III, who also wished to see Imperial power in Italy decline. At the Battle of Legnano on May 29, 1176, Frederick I was defeated and, by the Peace of Venice, agreed to a six-year truce from 1177 to 1183, until the Second Treaty of Constance, where the Italian cities agreed to remain loyal to the Empire but retained local jurisdiction over their territories.
The Lombard League was renewed several times and after 1226 regained its former prestige by countering the efforts of Frederick II to gain greater power in Italy. These efforts included the taking of Vicenza and the Battle of Cortenuova which established the reputation of the Emperor as a skillful strategist. 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 held out, and in October 1238 he had to unsuccessfully raise the siege of Brescia. Once again receiving papal support, the Lombard League effectively countered Frederick's efforts. During the 1249 siege of Parma, the Imperial camp was assaulted and taken, and in the ensuing Battle of Parma the Imperial side was routed. Frederick lost the Imperial treasure and with it any hope of maintaining the impetus of his struggle against the rebellious communes and against the pope. The League was dissolved in 1250 once Frederick died.
"Lombard League." Encyclopædia Britannica. 2008. Encyclopædia Britannica Online. 6 Apr. 2008 G. Fasoli,"La Lega Lombarda --Antecedenti,formazione, struttura," Problema des 12.Jahrhunderts,
Vortraege und Forchungegen, 12 ,1965-67)143-160.
G. Fasoli,"La Lega Lombarda --Antecedenti,formazione, struttura," Problema des 12.Jahrhunderts, Vortraege und Forchungegen, 12 ,1965-67)143-160.