In 1473, that zealous servant of Burgundy declared that if the burghers persisted in their refusal he would resort to force.  Their reply was that Mulhouse could not take such an important step without consulting her friends, the Swiss.  “Are the cantons going to help you pay your debts?” was the sneering comment of Hagenbach.  “Mulhouse is a bad weed in a rose garden, a plant that must be extirpated.  Its submission would make a charming pleasure ground out of the Sundgau, Alsace, and Breisgau.  The duke knew no city which he would prefer to Mulhouse for a sojourn,” were his further statements.[10]

Two days were given to the town council for an answer.  Hagenbach remarked that it was useless to think that time could be gained until the mortgaged territories should return to Austria.  “Far from planning redemption, Duke Sigismund is now preparing to cede to Charles le temeraire as much again of his domain and vassals.”  Still Mulhouse was not convinced that the only course open to her was to let Charles pay her debts and receive her homage.  No answer was forthcoming in the two days, but ready scribes had prepared many copies of Hagenbach’s letter, which were sent to all who might be interested in checking these proposals of Burgundy.

On February 24, 1473, a Swiss diet met at Lausanne and there the matter was weighed.  Hagenbach’s letter was shown to those who had not seen it, and methods of rescuing Mulhouse from her dilemma were carefully considered.  Years ago a union had existed between the forest cantons and the Alsatian cities.  There were propositions to renew this alliance so as to present a strong front to their Burgundian neighbour.  The cantons had enough to do with their own affairs, but the result of the discussion was that, on March 14th, a ten-year Alsatian confederation was formed in imitation of the Swiss.

The chief members were Basel, Colmar, Mulhouse, Schlestadt, and two dioceses, and it is referred to as the Basse-Union or the Lower Union, the purposes being to guarantee mutually the rights of the contracting parties, to meet for discussion on various questions, and, specifically, to help Mulhouse pay her debts.  A few days later, March 19th, there was a fresh proposition to make an alliance between this Basse-Union and the Swiss confederation.  This required a referendum.  Each Swiss delegate received a copy of the articles to take back to his constituents for their consideration.  No bond between the confederation and the union was, however, in existence at the time when Charles was approaching Alsace.  Various conciliatory measures on his part had somewhat lessened immediate opposition to him, but, nevertheless, there were frequent conferences about affairs.  Diets were almost continuous and there were strenuous efforts to raise money to free Mulhouse from her hampering financial embarrassments.