The Battle of Altopascio was fought in 1325 in Tuscany, between the Ghibelline forces of Lucca under Castruccio Castracani and those of Guelph Florence.
The latter's troops moved to face him, but Castracani preferred to avoid a pitched battle; he took shelter in the local burgh of Cerruglio, waiting for reinforcements from his allies, the Bonacolsi, the Visconti and Cangrande della Scala.
Besieged by the Florentine commander, the Catalan Ramon de Cardona, the small garrison of Altopascio (500 men) resisted for 26 days (August 3–29), but in the end they had to surrender to the greatly superior Guelph forces (15,000 infantry and 2,500 cavalry, mostly composed of French, German and Burgundian mercenaries).
The winners put their camp at Altopascio, but started to suffer heavy losses due to the unhealthy environment.
For his victory, he was granted the title of Duke of Lucca by Emperor Louis IV and the city offered him a veritable Roman Triumph, in which the Florentine carroccio was shown in the streets.