**In autumn 1632, the cantons of Bern and Solothurn clashed between Oensingen and Balsthal. Illustration by Marco Heer**

The Klus affair

In the autumn of 1632, Solothurn and Bern came within a whisker of going to war. A last-minute trade-off averted an escalation. A bloody tale from the Thirty Years’ War.

Adrian Baschung

Adrian Baschung is historian and director of the Museum Altes Zeughaus in Solothurn.

In the early winter of 1632, the Dünnern, a small tributary of the river Aare in the Solothurn Jura, gave up a gruesome discovery: the corpse of Hans Breiter, a soldier from the canton of Bern. This was the last unfortunate reminder of an event that had brought the Swiss Confederacy to the brink of civil war: the Klus Gorge attack of September 1632. The Klus Gorge in the Jura is located between Oensingen and Balsthal with the Dünnern running through it towards the river Aare. It was an important pass for centuries as it provided access to Basel via Oberer Hauenstein. There are many ruined castles and old forts around the gorge dating from the High Middle Ages, which testify to the area’s significance at that time. Two castles still feature prominently in this part of the Solothurn Jura. ‘Neu Bechburg’ near Oensingen can be seen from far away and was used to guard the southern access point, while ‘Alt Falkenstein’ was for keeping watch over the narrow northern exit in what is now Balsthal. In autumn 1632, Klus Gorge provided the setting for the event that brought Solothurn and Bern dangerously close to a military confrontation and threatened to destroy the fragile peace between the Protestant and Catholic sides.

Neu-Falkenstein castle on an 1820 painting. — *Neu-Falkenstein* castle on an 1820 painting. Swiss National Museum

Neu Bechburg by Oensingen, painted by Caspar Wolf, 1778. — *Neu Bechburg* by Oensingen, painted by Caspar Wolf, 1778. Wikimedia

Interdenominational tensions within the Confederacy had been, to say the least, fraught since the Reformation and Counter-Reformation. Although the Zweiter Kappeler Landfrieden (Second Territorial Peace of Kappel) had governed relations between Catholics and Protestants since 1531, mutual distrust persisted. This was exacerbated by the Thirty Years’ War (1618-1648). While the Reformed cantons looked towards the Protestant Union, the Catholic areas stayed loyal to the Imperial Catholic League. The Confederacy claimed neutrality in this battle for supremacy within the Holy Roman Empire. However, tensions within the country sparked by this devastating war threatened to tear the fledgling Swiss nation apart.

Bern versus Solothurn: a drama in several acts

The uneasy peace between Catholic Solothurn and pro-Reformation Bern was jeopardised by incidents that served to heighten the mutual distrust between the two cantons. For example, in April 1629 an ex-Capuchin monk who had converted to Protestantism, was arrested in Olten with his Bernese companion, a theologian. This led the villagers of Bätterkinden in the canton of Bern to attack a Capuchin friar from Solothurn. When Protestant Sweden entered the Thirty Years’ War, Protestant volunteers tried to serve in the Swedish forces, even though this was forbidden by the Federal Diet (‘Tagsatzung’). A platoon of Bernese mercenaries marched through the Klus Gorge in March 1632, without authorisation from the Solothurn authorities, to join the forces of Swedish King Gustav II Adolf (1594-1632). When Solothurn protested, the Bernese authorities merely claimed not to have been aware of it, which subsequently turned out to be a lie. The two cantons then agreed that in future Bern would have to obtain approval from Solothurn before conducting troop movements through its territory. Solothurn also reinforced its surveillance of the Klus Gorge, to the annoyance of its neighbours in the Bernese Oberaargau.

**Protestant soldiers were welcome among the Swedish troops of King Gustav II Adolf.** Wikimedia

Against this backdrop, an officer called Stein subsequently set off with 40 to 50 Bernese musketeers. Mulhouse on the other side of the Rhine felt threatened by the war and had called on its Protestant allies in the Confederacy for support. Bern responded by sending these soldiers. Lieutenant Stein chose to take the route through the Klus Gorge to reach Mulhouse via Basel. He reached the gorge on 16 September 1632 and requested passage. Bailiff Urs Brunner was watching over the pass from Falkenstein castle and refused Stein access as he had no written authorisation. The bailiff issued a written report to Solothurn on the same day. The next day, the Bernese moved from their camp in Niederbipp into the gorge. However, as there was still no word from Solothurn, Brunner again refused them access to the pass. This prompted the Bernese lieutenant to write a missive to Bern, in which he appears to have exaggerated the situation.

**Textbook with illustrations for practising with the musket, 1635.** Wikimedia

The Solothurn authorities found the presence of the Bernese soldiers disconcerting and asked Bern about their mission. At the same time, they refused to grant passage without written authorisation and instructed the bailiff at Bechburg, Philipp von Roll, to support his colleague at the northern end of the Klus Gorge. In the meantime, the authorities in Bern also reacted. They informed Solothurn about the reason for the troop movement, while also ordering Lieutenant Stein to continue his journey as the gorge was allegedly open. Both letters reached their addressees on 20 September. Having been kept waiting for several days, and with written authorisation from Bern in his hand, the now visibly angry Stein demanded access to the gorge from bailiff Brunner. Brunner had gathered 400 men from the area below Falkenstein castle and sealed off the path. He didn’t know that written authorisation had already been dispatched from Solothurn in all haste by messenger.

**No getting through: The Kluse affair in autumn 1632 was the peak of tensions between Bern and Solothurn. Illustration by Marco Heer**

The Bern and Solothurn contingents thus found themselves in a tense stand-off. Muskets at the ready, the soldiers’ hands gripped their weapons tightly as they wondered what would happen. Attack? Defend against attack? To show he meant business, bailiff Brunner had his guards and soldiers in the castle fire off warning shots. This made Lieutenant Stein back down and he reluctantly ordered his men to turn back. However, before they reached the cantonal border, they ran into 150 Solothurn soldiers at the southern end of the gorge. Alerted by the warning shots, the Bechburg bailiff, Phillip von Roll, had mobilised his men and they now pushed the Bern troops back into the Klus Gorge. So, there was another stand-off, with the Bernese hemmed in by the Solothurn forces to the north and south, between the walls of the gorge and beside the Dünnern river, which was heavily swollen by sustained rainfall.

Examples of 17th century matchlock muskets in the Museum Altes Zeughaus Solothurn. — **Examples of 17th century matchlock muskets in the Museum *Altes Zeughaus Solothurn*.** Photo: Nicole Hänni / Museum Altes Zeughaus

Bailiff von Roll, allegedly buoyed by Dutch courage, faced the trapped Bernese contingent and boorishly called on them to extinguish the smouldering fuses on their muskets. One Bernese private who failed to follow this instruction fast enough was thrown to the ground by one of von Roll’s men. This action seemed to cause Philipp von Roll to abandon all scruples. “Attack, leave none alive!” cried von Roll as he fired his pistol into the Bernese. In the same instant a shot was heard coming from Falkenstein and in next to no time the local peasantry was attacking the Bernese. All restraint was abandoned. The defenceless Bernese soldiers had only one option: to flee. But where to? The pass was blocked and the sides of the gorge were steep. Some sought refuge by jumping into the Dünnern. However, it was flowing so fast that many were swept along to a bridge where more hostile Solothurners were waiting armed with halberds and muskets. By the time bailiff Brunner had finally managed to restore order, nine Bernese soldiers had been killed. The Solothurn forces also took 28 prisoners, some of whom were wounded, and Lieutenant Stein was led away by 100 musketeers and placed under guard in the Klus Gorge. One man from Bern, Hans Breiter, was missing, the rest managed to escape. One hour later, the messenger from Solothurn arrived with written authorisation for the Bernese soldiers to pass through the gorge.

Bern dreams of revenge

There was an immediate response to this unwarranted attack. Bern was furious and demanded redress from Solothurn. The perpetrators were to be punished and considerable compensation was called for. On the Solothurn side, the two bailiffs and their influential families had many supporters. Solothurn was put on high alert in anticipation of an attack. Bern plotted retaliation, and both sides called on their allies for support in the event of a military confrontation. In the end, Solothurn asked the Federal Diet to set up an arbitration tribunal to establish the facts of the case.

**Johann von Roll, Mayor of Solothurn at the time, was the father of Philipp. Copperplate engraving from the early 18th century.** Wikimedia / Solothurn Central Library

Bern was in no doubt as to the identity of the guilty party: Solothurn would have to pay. The Federal Diet mainly sided with Bern. Following extensive negotiations, which included a number of attempted bribes by Solothurn, both bailiffs were removed from their posts and some of the people involved in the rampage were jailed. Bern was not satisfied; it mobilised its troops and imposed a trade embargo on Solothurn. For better or worse, Solothurn had no option but to launch court proceedings against both bailiffs, Brunner and von Roll. However, they had already absconded to Burgundy. The two men were sentenced in absentia ‒ Philipp von Roll to 101 years of exile and Brunner to six ‒ and their assets were confiscated.

Classroom mural of a Diet meeting. Issued by the Swiss Association of Teachers in 1947. — **Classroom mural of a Diet meeting. Issued by the *Swiss Association of Teachers* in 1947.** Ingold Verlag

But Bern wanted the “fratricide” avenged with blood, and both parties and their allies prepared for a military campaign. In order to prevent a civil war, the Catholic side gave way and Solothurn committed to reparations. In 1633, Solothurn paid the sum of 5,000 gold coins to Bern as compensation and condemned three people to death. They were executed by sword on 11 April in Solothurn.

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