Lower League

The Lower League ("Niedere Vereinigung, inferiores confederati") was a union of the four imperial cities Strasbourg, Basel, Colmar and Sélestat, formed in 1473, joined by the bishops of Basel and Strasbourg, Sigismund of Habsburg and by the Old Swiss Confederacy in 1474.
The name of the league is intended to distinguish it from the "upper" (highland) league of the Swiss Confederacy.
The league formed an anti-Burgundian pact, led by Strasbourg, Basel, Berne and Lucerne, in April 1474. 
This collaboration led contributed to the final defeat of Charles the Bold and the conclusion of the Burgundian Wars at the Battle of Nancy in 1477.
In the wake of the Burgundian Wars, Basel became a full member of the Swiss Confederacy, while collaboration between the Swiss and the cities of Strasbourg, Colmar and Sélestat would not be resumed.