The Swabian War of 1499 ( (spelling depending on dialect), called or ("Swiss War") in Germany and ("War of the Engadin") in Austria) was the last major armed conflict between the Old Swiss Confederacy and the House of Habsburg. What had begun as a local conflict over the control of the Val Müstair and the Umbrail Pass in the Grisons soon got out of hand when both parties called upon their allies for help; the Habsburgs demanding the support of the Swabian League, while the Federation of the Three Leagues of the Grisons turning to the Swiss Eidgenossenschaft. Hostilities quickly spread from the Grisons through the Rhine valley to Lake Constance and even to the Sundgau in southern Alsace, the westernmost part of the Habsburg region of Further Austria.
Many battles were fought from January to July 1499, and in all but a few minor skirmishes, the experienced Swiss soldiers defeated the Swabian and Habsburg armies. After their victories in the Burgundian Wars, the Swiss had battle tested troops and commanders. On the Swabian side, distrust between the knights and their foot soldiers, disagreements amongst the military leadership, and a general reluctance to fight a war that even the Swabian counts considered to be more in the interests of the powerful Habsburgs than in the interest of the Holy Roman Empire proved fatal handicaps. When his military high commander fell in the battle of Dornach, where the Swiss won a final decisive victory, Emperor Maximilian I had no choice but to agree to a peace treaty signed on September 22, 1499, in Basel. The treaty granted the Confederacy far-reaching independence from the empire. Although the Eidgenossenschaft officially remained a part of the empire until the Treaty of Westphalia in 1648, the peace of Basel exempted it from the imperial jurisdiction and imperial taxes and thus de facto acknowledged it as a separate political entity.
Background
One source of conflict was the ancient distrust, rivalry, and hostility between the Old Swiss Confederacy and the House of Habsburg, which had risen to the throne of the Holy Roman Emperor since 1438. Since the late 13th century, the members of the Swiss Confederacy had gradually taken control of territories that once had belonged to the Habsburg realm. The Swiss had attained the status of imperial immediacy, being subject only to the emperor himself, and not to any intermediate Princes or liege lords. This status granted them a far-reaching autonomy within the Holy Roman Empire, even more so as the emperor was a distant overlord. Before 1438, the empire and the emperor had been an antipole to the Habsburg dukes for the Swiss. Previous emperors had repeatedly supported the confederates in their struggles against the Habsburgs, whom they saw as strong rivals. They had confirmed the Imperial immediacy of the Swiss on several occasions; and the Swiss had succeeded in defending their privileged status against Habsburg dukes who had tried to regain their former territories.
Habsburgs in the Holy Roman Empire in the 15th century
When Frederick III of Habsburg ascended to the throne, the Swiss suddenly faced a new situation in which they could no longer count on support from the empire. Worse yet, conflicts with the Habsburg dukes threatened to become conflicts with the empire itself. Under Frederick's reign, this did not occur yet. Frederick had sided in 1442 against the confederacy in the Old Zürich War where he had supported the city of Zürich, and he also refused to reconfirm the imperial immediacy of the members of the Confederacy. But Frederick's troubled reign did not leave room for military operations against the Swiss. In Austria, Frederick was in conflict first with his brother Albert and then faced the pressure of Matthias Corvinus, who even drove him from Vienna and forced Frederick's court to assume an itinerant lifestyle.