did not allow any foreign army to cross its territory: the alpine passes remained closed for Spain, just as an alliance offer of the Swedish King Gustav Adolph was rejected. The sole exception was the permission for the French army of Henri de Rohan to march through the Protestant cantons to the Grisons. A common defence was mounted only in 1647 when the Swedish armies reached Lake Constance again. The Grisons had no such luck. The Three Leagues were a loose federation of 48 individual communes that were largely independent; their common assembly held no real powers. While this had helped avoid major religious wars during and following the Reformation, feuds between leading clans (e.g. between the von Planta and the von Salis) were common. When such a feud spilled over into the Valtellina in 1619, a subject territory of the Three Leagues, the population there responded in kind, killing the Protestant rulers in 1620 and calling Habsburg Spain for help. For the next twenty years, the Grisons was ravaged by a war known as the Confusion of the Leagues. For the Habsburgs, the Grisons was a strategically important connection between Milan and Austria. The Valtellina became Spanish, and other parts in the north-east of the Grisons were occupied and re-Catholicised by Austria. France intervened a first time in 1624, but succeeded to drive the Spanish out of the Grisons only in 1636. However, Henri de Rohan's French army had to withdraw following the political intrigues of Jürg Jenatsch, who managed to play the French off against the Spaniards. Until 1639, the Three Leagues had re-acquired their whole territory, buying back the parts occupied by Austria. They even were restituted their subject territories in the south (Valtellina, Bormio, and Chiavenna), yet these had to remain Catholic under the protection of Milan. The mayor of Basel, Johann Rudolf Wettstein, lobbied for a formal recognition of the Swiss confederacy as an independent state in the peace of Westphalia. Although de facto independent since the end of the Swabian War in 1499, the confederacy was still officially a part of the Holy Roman Empire. With the support of Henri II d'Orléans, who was also prince of Neuchâtel and the head of the French delegation, he succeeded to get the formal exemption from the empire for all cantons and associates of the confederacy. Social developments Historians count 13 (Geneva) or 14 (St Gallen) plague