Hans von Hallwyl, a Swiss army commander from Kanton Aargau, played a key role in the Old Swiss Confederacy's victory at the Battle of Morat in June 1476, as well as in the battle against Charles the Bold, Duke of Burgundy, at Grandson in March earlier that year. He belonged to the von Hallwyl family, which resided in Hallwyl Castle in Aargau, and in 1475 he married Magdalena von Rothenstein.
During the Battle of Murten, Hans led the Bernese vanguard and broke through the front-line defence of the Burgundians at Grünhag, securing their main camp. He fought alongside Duke Renatus of Lorraine and defeated the Burgundian soldiers, despite heavy attack by archers, crossbowmen, and artillery. The Confederates proved largely resistant to the assault, and as reinforcements from the main Burgundian force arrived too late, about half of the Burgundian army was killed by the Confederates and their allies, while Charles the Bold escaped with his remaining men.
After the Battle of Morat, von Hallwyl continued his military career. He served Duke Albrecht VI of Austria in Alsace alongside his brother Walter the seventh before becoming a war contractor in Bohemia and Hungary. He served the city of Bern in 1470 after the successful Burgrecht of his family representatives. Later, he served King Louis XI of France and became the supreme captain of the Confederate mercenaries in 1480 as well as the councillor and chamberlain of Emperor Frederick III.
In 1486, he acquired the lower court of Rupperswil and the lordship of Trostburg including the castle and villages belonging to it. Although he mostly lived in Aarau, he also participated in the Swabian War in 1499 as an army commander.