In 1419, the Swiss cantons of Uri and Unterwalden bought the fortified town of Bellinzona from the House of Sax but were unable to defend it adequately.

A Swiss attempt to recapture Bellinzona with the support of other cantons including Lucerne and Zug led to the battle at the village of Arbedo, 3 km (1.9 mi) north of the town.

Carmagnola then brought up his crossbowmen on the Swiss flanks and ordered his men-at-arms to dismount and fight on foot with their lances, which outreached the halberds.

When the Milanese force pulled back to reform, the Swiss withdrew from the battlefield, both sides having taken heavy casualties.

In addition, the Duchy regained the Val d'Ossola, thus the Swiss lost all their territorial gains.