The Swiss frontier in the First World War

Since Switzerland was a neutral country, its frontiers had to be guarded to prevent the warring armies crossing them, deliberately or accidentally. However there were occasions when the border was crossed...

Image: A Swiss soldier (foreground) talks to a German border guard through the frontier wire.

The start of the war was one of the points at which there was the greatest fear amongst the Swiss of invasion, in case the French or Germans tried to gain an advantage by outflanking their enemy through Switzerland. The frontiers were guarded by the Swiss army. Above: The frontier at Basle, blocked at the start of the war.

In places the frontier had considerable defences, including bunkers and barbed wire, similar to those used by the opposing sides in combat. However as this image shows, in places away from the fighting little separated the Swiss and their neighbours. Although Switzerland is a small country, the frontier was 1,400km (870 miles) in length, and could not be guarded in great strength everywhere! There are said to have been some 1,000 violations of the frontier during the war.

The Swiss strictly enforced their frontier. Under international law, troops from the belligerents who crossed the Swiss border (for whatever reason) had to be interned. Above is part of a patrol of 21 German soldiers who crossed frontier in 1914 and were interned (with a Swiss soldier in darker uniform at far left).

French, German, Italian, British or American aircraft also sometimes accidentally crossed onto Swiss soil. In certain cases the plane landed because the airmen did not realise they had crossed the frontier, while other times injuries to the crew meant they had to land immediately. Below is a German aircraft that landed at Bellach (about 30km or 19 miles from the frontier) on 13 October 1916.

Very occasionally, Swiss territory was actually attacked, most frequently through being bombed by aircraft. The town of Porrentruy was bombed several times. It was located in a small section of Swiss territory that projected out into France, and was only about 12km or 7 miles away from the point where the Western Front (the French and German front lines) met the Swiss frontier. This seems to have meant that there was potential for either side to make a navigational error and drop bombs on Swiss land. The house in Porrentruy seen below was damaged by bombs on 24 April 1917. Generally casualties were very light, though this was down to chance as much as anything else. (see here for a detailed account of one such bombing raid at La Chaux-des-Fonds, in French.)

Bombing incidents in the Porrentruy area were so frequently that a large cross, at least 20 metres wide, was placed near the town in order to indicate to even high-flying aircraft that it was in Swiss territory. The cross can be seen on the left side of the above image. Apparently it had electrical illumination so that it was even visible from the air at night! More active methods were also taken, such as the deployment of anti-aircraft guns (image below: a standard artillery piece on a special rotating mounting), the fire from which sometimes forced down belligerent aircraft that had strayed across the border.

On 7 October 1918, Swiss neutrality was infringed in an attack that caused great public controversy in Switzerland. An observation balloon tethered between Miécourt and Cornol (near Porrentruy, around 2-3km (1.5 miles) over the border into Switzerland) was shot down by a German aircraft. The burning balloon fell to earth and the Swiss soldier acting as observer, Lieutenant Walter Flury, was killed. Some Swiss newspapers questioned whether the attack was really an error or had been pre-planned, since the balloon was clearly marked as Swiss. Below is a balloon similar ​to the one that was shot down. Such apparently direct attacks were very rare however.

It was easy to fly over the Swiss border, but could it be crossed on land? Well, people certainly tried.

The two Serbian soldiers show below, Sergeant Lioubomir Romich (left) and private Svetozar Markovitch (right), had been captured by the Bulgarians and Austro-Hungarians respectively. In 1916, after spending two months working on a German farm they managed to escape. They travelled for 13 days until they managed to cross the Swiss frontier. In the centre of the photo is Johann Weber, the Swiss soldier who then escorted them to Geneva. The British soldier A.J. Evans, who wrote the book "The Escaping Club", also managed to get into Switzerland from Germany after 18 days on the run. Not everyone who tried to make the crossing was successful. On 10 April 1917, a Russian prisoner of war being held in Germany tried to cross to Switzerland, but was shot by the Germans as he did so.

Deserters also crossed the frontier. In the 1920s, a high-ranking Reichswehr (German army) officer estimated that 9,000 German deserters fled to Switzerland during the First World War! (information from Dr. Benjamin Ziemann)

Did anyone manage to make the crossing in the other direction? In 1916 two French airmen who escaped back to France from Switzerland: pilot Sergeant Madon (below, at left) and mechanic Corporal Chatelain (below, at right). Neither man had agreed to give his parole (his word) that he would not try to escape. They managed to get from Zurich to Lausanne, and then to ​Evian-les-Bains, which is on the other side of Lac Leman from Lausanne. 

If these men could cross the Swiss frontier, then no doubt spies could as well. But that is another story (that I need to research!). Actually, many spies would travel freely across the frontier, perhaps using the cover of being diplomatic or other government personnel for their nation.

Also on this website: "Kilometre Zero: Where the Swiss frontier met the Western Front.