On 29 May 1176, the imperial army of Frederick I Barbarossa ⓘ met the forces of the Lombard League ⓘ near the town of Legnano, northwest of Milan. The encounter proved decisive in the long struggle between imperial authority and the autonomous communes of northern Italy.

Frederick led a force of roughly 3,000 men, including heavily armoured German knights. Opposing him stood the combined militias of the Lombard League, numbering perhaps 10,000–12,000. At the centre of the League’s army stood the carroccio, a fortified ceremonial war wagon bearing the communal standard — both tactical anchor and civic symbol.

What may have begun as an unplanned confrontation became a sustained and violent engagement. Lombard infantry, fighting in disciplined formations and exploiting the broken terrain of ditches and hedges, withstood repeated cavalry assaults. During the battle Frederick was unhorsed and temporarily disappeared in the mêlée, giving rise to rumours of his death and contributing to the collapse of imperial morale. His forces broke and retreated in disorder.

The Lombard League achieved a clear victory. The defeat ended Barbarossa’s fifth and final Italian campaign and forced a shift from military coercion to diplomacy. The subsequent Peace of Venice (1177) and the Peace of Constance (1183) recognised the League’s existence and granted the communes substantial rights of self-government, while maintaining nominal imperial sovereignty.

The Battle of Legnano became an enduring symbol of communal resistance to imperial domination. In the nineteenth century it acquired renewed political significance during the Risorgimento. La battaglia di Legnano, composed by Giuseppe Verdi in 1849, invoked the medieval victory as a patriotic allegory of Italian unity against foreign rule. Its overtly nationalist tone led to censorship and prohibition in territories under Habsburg control.

Today, 29 May is commemorated in Lombardy as a regional holiday, and the battle remains a foundational episode in the political mythology of northern Italy.