thumb|left|Memorial in [[Giornico]]
In the Battle of Giornico, also known as the battle of large rocks (Italian: Battaglia di Giornico, dei Sassi Grossi; German: Schlacht bei Giornico) (28 December 1478), about 600 Swiss troops ambushed from above and defeated a larger force of the Duchy of Milan, confined in a narrow icy valley, by rolling large boulders down the hillside against the Milanese.
History
The Battle of Giornico was part of an expansionist policy of the Old Swiss Confederation during the 15th century. The confederation attempted to expand into the southern foothills of the Alps to gain control of both ends of the valuable mountain passes. In November 1478, troops of the Canton of Uri moved south over the Gotthard pass into the Leventina valley. The population of the valley, who had long been opposed to Milan, greeted the Swiss troops as liberators and allies. However, below the valley at Bellinzona, they found the city gates closed. Uri was quickly joined by forces from other Confederation cantons and established a siege camp below the walls of Bellinzona on 30 November 1478. The Duke of Milan responded by sending 10,000 men toward Bellinzona to drive the Confederates back and reassert his control over the Leventina.
The battle
On 16 December the Milanese army reached Magadino on Lake Maggiore about from Bellinzona. However, the Confederates had already retired, after a 14-day siege of Bellinzona, to the Gotthard Pass. Only a 175-strong reserve army, reinforced by about 400 soldiers from the Leventina, were guarding the rear at Giornico in the Leventina valley.