The Raron affair was a 15th-century rebellion in the Valais region against the power of a local noble family, the Raron family. The rebellion brought several cantons of the Swiss Confederation into conflict with each other and threatened a civil war in the Confederation. While Bern was initially successful, they were eventually forced to surrender most of their gains.
At the end of the 14th and beginning of the 15th Centuries, the Baron of Raron rapidly rose to the highest ecclesiastical and secular offices in the Valais. After the death of Bishop William I of Raron in 1402 and his father Peter of Raron in 1413, a rebellious party formed in the Upper Valais. They were opposed to the new Prince-Bishop Wilhelm II of Raron and the power claims of his uncle Witschard of Raron. Emperor Sigismund had granted Witschard sovereignty over the Valais in 1414 as a reward from his military service in Lombardy. The rights over the Valais had been granted to the office of the Bishop of Sion in 999. The 1414 Imperial grant was supposed to transfer these rights from the office of the Bishop to the Raron family. The Zenden from Sierre to Goms were not willing to have gained independence from Savoy to then lose it to a local noble. Throughout the Valais unrest turned into talk of rebellion. Under the leadership of the Dog Society (so called due to the dog in its banner) in Brig, in 1415 this talk exploded into open rebellion.
The rebels besieged Witschard and his entourage at Seta Castle near Savièse and forced his resignation as episcopal bailiff along with the right to elect their own representatives in the government. A short peace was followed by additional fighting in 1416. Witschard allied himself with the House of Savoy, while Zenden of Goms entered into a treaty with Lucerne, Uri and Unterwalden.
The Zenden troops destroyed Beauregard, Tourbillon and Montorge castles. Witschard then secured the support of Bern, which split the Swiss Confederation. The neutral cantons, Schwyz, Glarus, Zurich and Zug attempted to intervene and restore peace. However, this was unsuccessful and in September 1417 Witschard and his family had to flee the country permanently. After another failed negotiations with Bern in 1418, Bern invaded over the Sanetsch Pass and plundered Sion. In 1419, they attempted another invasion across the Grimsel Pass. Bern repeatedly attempted to get Lucerne, Uri and Unterwalden to switch sides and prevent a civil war in the Confederation. Their failed invasion in 1420, convinced Bern to seek a peaceful resolution. In the Evian peace Bern and Witschard agreed to repayments and returned the items stolen from the cathedral in 1418. However, the power of the family of Raron in Valais remained broken.