These treaties were of immense importance for the history of Alsace and of Colmar. They put an end to a conflict that had been tearing Europe apart since 1618, recognised the victory of Sweden and France and hastened the end of the Holy Roman Empire.
There were in fact two treaties of Westphalia. The first one, drawn up between Sweden and the Empire in Osnabrück, laid down religious tolerance across the Empire. Goods and rights were to be restored to those who held them on 1st January 1624, the "standard year". Members of the Reformed church (Calvinist) were to enjoy the same rights as those granted to the Lutherans in the Peace of 1555.
The second treaty, drawn up in Munster, had a more political slant. It gave France, a latecomer to the war, the chance to push up some important pawns on the diplomatic chessboard. The preliminary peace agreement of 13 September 1648 gave France the Hapsburgs´ possessions in Alsace, while the imperial cities would remain within the immediacy of the Empire.
When the treaties were signed, on 24 October 1648, nothing much had changed, despite intensive diplomacy and the efforts of people such as Balthasar Schneider of Colmar. The King of France had won ownership of the Hapsburg lands in Alsace, which made up about four fifths of Upper Alsace. The House of Austria had ceded to France the Sundgau and Brisach, the Austrian seigniories with Ensisheim and the landgraviat (principality) of Upper Alsace. The landgraviat of Lower Alsace also came under the French crown, along with the great imperial bailiwick which had been in Hapsburg hands since 1558 and it was to this great bailiwick that belonged the forty villages and ten imperial towns and cities of the Décapole.
The threat was therefore real and it appeared that the Décapole towns could be split from the Empire. The Treaty of Munster, however, showed itself to be a true child of diplomatic ambiguity, giving the barons, cities and towns of Alsace the paradoxical and parallel "immediacy of the Empire", just like under the Hapsburgs. The equivocal sentence that followed revealed the limits of the concession: "without the sovereign rights of the King being in any way reduced".
The Treaty of Munster was one step in the gradual integration of Alsace within France. Its contradictions left it wide open to varying interpretations, which allowed Colmar and the other members of the Décapole the frail, lingering hope that they could remain within the Empire. The Alsace question had begun…