The founding of the Old Swiss Confederacy began in the late 13th century amid political instability following the death of Rudolf I of Habsburg in 1291. The Waldstätten (Uri, Schwyz, and Unterwalden), which had gained Reichsfreiheit (imperial immediacy) under the Hohenstaufen dynasty to control key trade routes like the St. Gotthard Pass, feared losing their autonomy under increasing Habsburg influence.
Rudolf's death triggered a power struggle between his son Albert I and Adolf of Nassau for control of the German throne, weakening Habsburg authority over the alpine regions. In response, the Waldstätten allied for mutual defense. On August 1, 1291, they formed an Everlasting League, documented in the Federal Charter of 1291, marking the beginning of the Swiss Confederacy.
The Habsburgs, however, did not abandon their efforts to reassert dominance. When Albert I’s successor Henry VII officially confirmed Unterwalden’s Reichsfreiheit in 1309, the three cantons renewed their alliance. In 1315, tensions with the Habsburgs escalated into open conflict. Schwyz, embroiled in a dispute with the Abbey of Einsiedeln, faced an invading Habsburg army led by Leopold I. The Forest Communities dealt the Habsburgs a decisive defeat at the Battle of Morgarten in 1315, reinforcing their independence.
Following the victory, the three cantons solidified their unity through the Pact of Brunnen, reaffirming their status as reichsfrei territories. Although later Swiss chronicles like the White Book of Sarnen described the period as one of coordinated castle destructions (Burgenbruch), archaeological evidence suggests that many castles were gradually abandoned rather than destroyed in a single uprising. Nonetheless, this alliance laid the foundation for the Old Swiss Confederacy, marking the region’s first steps toward collective self-governance and independence from external rule.