The Battle of Legnano was a battle between the imperial army of Frederick Barbarossa and the troops of the Lombard League on May 29, 1176, near the town of Legnano in present-day Lombardy, in Italy. Although the presence of the enemy nearby was already known to both sides, they suddenly met without having time to plan any strategy.The battle was crucial in the long war waged by the Holy Roman Empire in an attempt to assert its power over the municipalities of Northern Italy, which decided to set aside their mutual rivalries and join in a military alliance symbolically led by Pope Alexander III, the Lombard League.The battle ended the fifth and last descent into Italy of Emperor Frederick Barbarossa, who after the defeat tried to resolve the Italian question by adopting a diplomatic approach. This resulted a few years later in the Peace of Constance (June 25, 1183), with which the Emperor recognized the Lombard League and made administrative, political, and judicial concessions to the municipalities, officially ending his attempt to dominate Northern Italy.The battle is alluded to in the Canto degli Italiani by Goffredo Mameli and Michele Novaro, which reads: «[...] From the Alps to Sicily, Legnano is everywhere [...]» in memory of the victory of Italian populations over foreign ones. Thanks to this battle, Legnano is the only city, besides Rome, to be mentioned in the Italian national anthem. In Legnano, to commemorate the battle, the Palio di Legnano takes place annually from 1935, on the last Sunday of May. In the institutional sphere, the date of May 29 was chosen as the regional holiday of Lombardy.