In the late 15th Century the Duchy of Burgundy and the confederation of cantons that would become Switzerland were both attempting to gain control of new lands. When in 1469 Charles the Bold, fourth of the Valois Dukes of Burgundy acquired Alsace from the Duke of Austria he also acquired the rebellious towns of the area that were allied with the Confederation. This led to war in 1474.
The Canton of Bern sent troops into the Vaud region of Burgundy to gain control of the passes through the Jural mountains to prevent the passage of Italian recruits to Charles' army. They destroyed all of the Burgundian castles in the Vaud region except Grandson. Grandson castle on the Northwest shore of Lake Neuchâtel was the key to controlling the mountain passes. The Bernese forces occupied Grandson and several surrounding towns, cutting of the passes to Savoy.
Charles set out from Besancon with an army of 11,000 men on February 6, 1476 to retake the area captured by the Confederates. Charles' army consisted of cavalry, made up of Burgundian Knights and men-at-arms and mercenary foot troops including pike men, gunners, archers, and crossbow men. Charles crossed into the Vaud on the 12th. On the 21st he captured the town of Grandson and laid siege to the castle. The castle held for a week, but on the 28th the Bernese defenders surrendered. Charles had all 412 of the Bernese executed. On the evening of the 28th the Confederation forces, numbering 20,000 camped near Neuchâtel. The next day, the 29th, Charles reconnoitered the area to his East and found the Confederation forces. He placed 300 members of his household guard in the ruined castle at Vaumarcus.
This area of the lake shore was dominated by the forested slopes of Mount Aubert. In between Vaumarcus and Concise, the forest came all the way down to the lake shore, for a distance of around two and a half miles. To the west of this forested area, a plain expanded outward from the shore to a maximum width of a mile.
The Confederation forces moved Westward on March 1st and camped for the night near Boudry. During the evening they received word of the execution of the defenders of Grandson. A war council was held and they decided to attack Vaumarcus the next day. Before dawn on March 2nd the confederation troops were roused and fed then formed up for the attack on the castle.
Charles formed his army on the plain a little over a mile from the edge of the woods. He divided his army into three divisions. Infantry and guns in the center and his cavalry on both wings.
A portion of the Confederate forces assaulted Vaumarcus castle while the rest of the army moved to the West into the forest. As the Burgundians in the castle held of the attack there, an advanced party of gunners and crossbow men ran into a scouting group of Charles army. The fire from the early hand guns and crossbows drove off the Burgundian troops armed with longbows. The Burgundians retreated Westward out of the forest. The rest of the Confederate troops, numbering about 9,000 moved forward to the edge of the woods and found themselves facing the bulk of Charles army. Around 11 o'clock the Confederation forces formed up in a square or phalanx with a line of 300 skirmishers armed with hand guns and crossbows in front. The square was 100 men wide. In the center of the square were men armed with halberds surrounded by eight rows of pike men.
The square began to advance, supported by a few cannons manned by men from Bern set up on their left. The Burgundian artillery opened fire. Charles had 200 cannon arrayed against the oncoming Confederates. The tightly packed square was ravaged by the cannon fire, as many as 10 men being hit by one cannon ball. But the square continued to advance. The Bernese cannon replied with telling effect.
Charles replied by ordering the cavalry on his right to attack the enemy. As the Burgundian cavalry armed with 10 foot lances advanced many were hit by fire from the skirmishers. As the cavalry closed the skirmishers fell back to the protection of the square. The pike men in the front prepared to meet the cavalry charge. The front ranks grounded their 16 foot pikes and held them low to the ground. The next rank grounded theirs and held them higher. While the next two ranks held their pikes at waist and head level respectively. The Burgundian's horses first slowed and then stopped, unwilling to charge a wall of sharpened steel. The two sides thrust at each other briefly, then the cavalry turned and rode away to reform for another charge. Charles formed his personal guard into a wedge and led another charge on the square, with much the same result as the first charge. He then ordered the cavalry on the left to enter the woods to flank the Confederation troops. Unable to move quickly through the tangled terrain the cavalry came under fire from hand guns and crossbows, many were killed and more wounded. The remnants of the cavalry succeeded in hitting the rear corner of the square but did not have sufficient force to break the formation.
The Burgundian cavalry mounted charge after charge against the pikes and halberds. In between charges the Burgundian cannons and archers fired into the square over and over. The Confederates were taking casualties from the repeated attack and after several hours Charles decided to change his tactics. He was going to try to lure the Confederates out from the edge of the woods so his cavalry could charge their flanks and rear. To do this he moved his cannons to the wings, formed his cavalry to the outside of the guns, and ordered the infantry in the center to fall back to lure the enemy forward. Unfortunately for Charles, just as his infantry began to move back the rest of the Confederate army arrived on the field. The men from the cantons of Lucerne, Uri, and Unterwalden were mounted on war horses. This force fell upon the Burgundian infantry, totally routing them. The other reinforcements and the rest of the troops in the square followed the cavalry and forced Charles to retreat to the West. Charles was forced to leave behind his cannon and baggage train. The Confederate force being composed mostly of foot troops was unable to pursue the Burgundians. So they settled for looting the Burgundian camp.
Total dead at the battle of Grandson amounted to around 300 Burgundians and 200 Confederates. This doesn't take into account the large numbers wounded by crossbows and arrows. Between the army and the recaptured castle the Confederates acquired almost 400 cannons, a fact that would come to haunt Charles in the years to come.