The town of Bellinzona was the chokepoint between the Swiss cantons above the St Bernard Pass in the north and the Po Valley via the Ticino river valley to the south. In 1419, during the confusion after Duke Gian Galeazzo Visconti died, several cantons of the Swiss Confederation bought the town from the Duchy of Milan, ostensibly to protect trade. Instead, Bellinzona became a staging area for the aggressive Swiss to raid vulnerable Milanese possessions. In early 1422, an exasperated Milan forcibly took the town back. The Swiss invaded.

The rise of the Duchy of Milan in the early Renaissance was due to the wealth and efforts of the powerful and ambitious Visconti family, and the military prowess of their chosen commander, the condottiero (a contracted mercenary warlord) Francesco Bussone of Carmagnola. Over the years, Bussone made short work of Visconti and Milanese rivals in northern Italy, but he’d be put to the test by the Swiss.

The defense of the fertile but isolated alpine valleys and plateaus forged a tough and independent Swiss people protected by formations of soldiers that differed in composition from their traditional enemies whom surrounded them on all sides. The relative lack of horses in the central Alps saw the prominence of infantry among its minor nobles. Moreover, the defense of the narrow passes against armies that relied upon the heavily armored mounted knight, gave rise to the extensive use of the halberd among the Swiss. A halberd is essentially an axe head attached to the top of a six to nine foot pole, with a spear head, a hook opposite the axe head, and a butt spike. Against horsemen it was a fearsome weapon: one could receive the charge with the spear point, chop the horse with the axe head, or pull the rider off the saddle with the hook, and finally quickly finish the vulnerable knight on the ground with the spike. In the 14th century the halberd was for all intents and purposes the Swiss national weapon, and they fielded forests of them.

In early April 1422, Bussone attacked the invading Swiss army with his mounted knights. The Swiss handily defeated them and continued on toward Bellinzona. But Bussone was a professional and wasn’t going to let the Swiss besmirch his so far untarnished reputation. He reorganized his army around defeating the halberd. He dismounted most of his knights and equipped them with pikes. Whether or not Bussone was influenced by the rediscovery of Ancient Greek and Roman texts that characterized the Renaissance in Italy by doing so is a subject for scholarly debate; the fact remains that Bussone’s new pikemen would not have been out of place among Alexander the Great’s sarrissa equipped phalanxes 1600 years before.

On 30 June 1422, Bussone met the Swiss outside the town of Arbedo. It was not be a repeat of the previous battle. The Milanese pikemen had an asymmetric four to six foot reach advantage over the Swiss halberdiers. The Swiss attempted to use their crossbowmen, the traditional counter to polearm wielding formations that were vulnerable to missiles, but they were chased back into the mass of halberds by the remaining Milanese knights. Bussone brought up his own crossbowmen, who poured fire into the flanks of the Swiss halberdiers.

Unable to mass their own crossbowmen, and possessing no cavalry to counter the Milanese crossbowmen, the Swiss were slowly but surely ground down by the pikemen. The Swiss took massive casualties, and could do nothing except retreat or be annihilated. They were saved from total destruction due only to a group of foragers who appeared on the Milanese flank and Bussone mistook them for another Swiss formation. The Milanese reformed against the new “threat”, and the defeated Swiss escaped.

The Battle of Arbedo checked Swiss ambitions in Italy for decades. However, they also took notice of the reasons for their defeat. Thereafter the Swiss almost universally adopted the pike as the new weapon for their infantry, and the halberd as a weapon wielded by the officers and file leaders.

For the next hundred years, phalanxes of mercenary Swiss pikemen would dominate warfare in Italy and Western Europe.