The Treaty of Basel concludes the Swabian War.

The Treaty of Basel of 22 September 1499 was an armistice following the Battle of Dornach, concluding the Swabian War, fought between the Swabian League and the Old Swiss Confederacy.

The Swabian War of 1499 (Alemannic German: Schwoobechrieg, called Schwabenkrieg or Schweizerkrieg in Germany and Engadiner Krieg 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.

September 22 is the 265th day of the year in the Gregorian calendar; 100 days remain until the end of the year.