Sonderbund War

The immediate trigger of the Sonderbund War was the Federal Diet's vote in July 1847 to dissolve the Sonderbund alliance by force, after the seven Catholic cantons that had formed it refused to comply with the Diet's demand for its dissolution^[1]. That decision set the Swiss Confederation on a path to armed confrontation within months, but the conditions that made such a confrontation possible had been accumulating for decades, rooted in the unresolved tension between cantonal sovereignty and the drive toward a more centralized national state.

The structural political cause lay in the deep constitutional ambiguity of the Swiss Confederation itself. Since the Restoration settlement of 1815, Switzerland had functioned as a loose compact of largely sovereign cantons, each jealously guarding its own laws, religion, and administrative arrangements. From the 1830s onward, a wave of liberal revisions swept through the constitutions of several Protestant and mixed cantons, concentrating executive power, expanding popular suffrage, and pressing for a revision of the federal compact that would shift meaningful authority from the cantons to a central government^[2]. To the leadership of the conservative Catholic cantons — Uri, Schwyz, Unterwalden, Lucerne, Zug, Fribourg, and Valais — this trajectory represented an existential threat to their confessional identity and self-governance.

The religious dimension was inseparable from the political one. The liberal cantons had moved against religious institutions: Aargau dissolved its monasteries in 1841, and Lucerne's brief experiment with inviting the Jesuits to staff its higher schools provoked fury from liberal and Protestant opinion across the Confederation^[3]. The Jesuit question became a flashpoint, with the Diet eventually voting to expel the order from Switzerland — a measure the Catholic cantons regarded as a direct assault on their confessional autonomy. It was precisely to resist such measures collectively that the seven cantons concluded their defensive alliance, the Sonderbund, in December 1845^[4].

The geopolitical context sharpened the urgency on both sides. The great conservative powers of Europe — Austria, France under Guizot, and the papacy — were sympathetic to the Sonderbund and at various points signaled their willingness to intervene diplomatically, or potentially in other ways, on its behalf^[5]. Swiss liberals were acutely aware that delay favored the Catholic cantons' external patrons; the Diet's general, Guillaume-Henri Dufour, was accordingly authorized to prosecute the campaign with speed^[6]. The liberals also understood that a Europe convulsed by the revolutions that would erupt in 1848 would be unable to act in time if the federal forces moved decisively. The Sonderbund War was thus fought in the shadow of a wider European contest between the principles of liberal nationalism and conservative order^[7].

The defeat of the Sonderbund in November 1847 was followed with unusual speed by a fundamental constitutional transformation. Within months of the campaign's conclusion, a constituent assembly drafted a new federal constitution, adopted in September 1848, which replaced the loose confederal Diet with a bicameral Federal Assembly and a collegial Federal Council — a framework modeled in part on American constitutional practice and in part on the liberal cantons' own regeneration-era constitutions^[1]. The new constitution transferred sovereign competencies over customs, currency, and the postal service to Bern, establishing for the first time a genuinely federal Swiss state rather than a treaty alliance among cantons. The brevity of the war — roughly three weeks of operations, with the decisive engagements including the Battle of Geltwil concluded at minimal cost in lives — meant that the victorious liberal majority could proceed from military success to constitutional revision without the economic exhaustion or political bitterness that more prolonged civil conflicts typically produce^[2].

The settlement deliberately incorporated the defeated Catholic cantons into the new federal structure rather than penalizing them through territorial annexation or punitive indemnities. General Guillaume-Henri Dufour, who commanded the federal forces, had conducted the campaign with conspicuous restraint, and the moderation of the peace reflected that ethos^[3]. The seven Sonderbund cantons — Lucerne, Uri, Schwyz, Unterwalden, Zug, Fribourg, and Valais — retained their cantonal identities, their confessional character, and their representation in the new bicameral legislature. This arrangement preserved the social and religious pluralism that had defined Swiss public life since the Reformation, even as it subordinated cantonal sovereignty to federal law on matters of common interest^[4].

The geopolitical consequences were shaped as much by the revolutionary context of 1848 as by the war itself. The great powers — Austria, France, Prussia, and Russia — had been prepared to intervene on behalf of the Catholic cantons and the principle of legitimate conservative order, but the speed of Dufour's campaign denied them the opportunity^[5]. When the revolutions of 1848 subsequently convulsed every major continental state, Switzerland found itself already constitutionally settled, an island of orderly liberal governance amid widespread upheaval. The country became a refuge for liberal and radical exiles expelled from the German states, the Habsburg Empire, and France — a role that reinforced both its reputation for asylum and the ideological character of its new federal institutions^[6].

The war did not resolve every structural tension it exposed. The confessional divide between Protestant and Catholic cantons remained a live fault line in Swiss political culture well into the late nineteenth century, surfacing in disputes over the Jesuits — whose expulsion the 1848 constitution mandated — and in the Kulturkampf controversies of the 1870s that replicated across the Swiss federation many of the same clerical-anticlerical conflicts visible in Bismarckian Germany. Nor did the 1848 settlement fully satisfy liberal centralizers: a revised constitution in 1874 extended direct-democratic instruments, including the legislative referendum, and further consolidated federal authority. The Sonderbund War was thus less a resolution of the underlying tensions between cantonal sovereignty and federal integration than the moment at which those tensions were permanently reframed within a constitutional rather than a military register^[7].