The Lombard League (Lega Lombarda in Italian) is an alliance formed around 1167, which at its apex includes most of the cities of northern Italy (although its membership changes in time), including, among others, Crema, Cremona, Mantua, Piacenza, Bergamo, Brescia, Milan, Genoa, Bologna, Padua, Modena, Reggio Emilia, Treviso, Venice, Vercelli, Vicenza, Verona, Lodi, Parma and even some lords, such as the Marquis Malaspina and Ezzelino da Romano.

The League is formed to counter the Holy Roman Empire's Frederick I, who is attempting to assert Imperial influence over Italy.

Frederick claims direct Imperial control over Italy at the Diet of Roncaglia (1158).

The League has the support of Pope Alexander III, who also wishes to see Imperial power in Italy decline.

At the Battle of Legnano on 29 May 1176, Frederick I is defeated and, by the Peace of Venice, which takes place in 1177, agrees to a six-year truce from August, 1178 to 1183, until the Peace of Constance, where the Italian cities agree to remain loyal to the Empire but retain local jurisdiction over their territories.The Lombard League is renewed several times and after 1226 regains its former prestige by countering the efforts of Frederick II to gain greater power in Italy.

These efforts include the taking of Vicenza and the Battle of Cortenuova, which establishes the reputation of the Emperor as a skillful strategist.

He misjudges his strength, rejecting all Milanese peace overtures and insisting on unconditional surrender.

It is a moment of grave historic importance when Frederick's hatred colors his judgment and blocks all possibilities of a peaceful settlement.

Milan and five other cities hold out, and in October 1238 he has to unsuccessfully raise the siege of Brescia.

Once again receiving papal support, the Lombard League effectively counters Frederick's efforts.

During the 1249 siege of Parma, the Imperial camp is assaulted and taken, and in the ensuing Battle of Parma the Imperial side is routed.

Frederick loses 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 is dissolved in 1250 once Frederick dies.