Seyssel: How a Former International Border Still Divides My Town
Today the divisions exist only on paper, yet the town still has two of most everything
On most mornings, the Rhône River runs swiftly between the Alps and the Jura, a long murky corridor that seems designed to divide.
On one bank sits Seyssel-Ain, and on the other, Seyssel-Haute-Savoie. One river, one name, but two towns, along with a stubborn history that refuses to change.
You can stand in the middle of the bridge, look left, then right, and feel as though the boundary between the towns makes no sense.
But it once did, way back when this stretch of the Rhône marked a firm border between two states.
Two towns that insist on being one
My side*, Seyssel-Ain, is the smaller of the two, with roughly 1000 people on the southwestern bank of the mighty Rhône River. Across the bridge is Seyssel-Haute-Savoie, with a little over 2300 residents. Each side runs its own affairs: two mairies (town halls), two cafés, two schools, two butchers, two banks, two pharmacies… you get the picture. Each side even has its own weekly market, Saturdays on the Ain side and Mondays in the Haute-Savoie.
In everyday life, we treat the boundary like background noise, but the administrative separation is very much there.
Why don’t they just merge?
To understand that, we’ll have to cross a lot more than a bridge.
One Seyssel through history
Archaeology has unearthed evidence of Stone and Bronze Age settlements on both sides of the Rhône, and long before the Romans imposed themselves, the Allobroges controlled the region. They defended it fiercely and resisted Roman taxation and Roman law so well that Caesar himself had to visit in person. He ordered a chain of defensive posts along the river, including one at Seyssel, guarding a strategic natural crossing between Geneva and the interior of Gaul.
You may remember the story of Hannibal, the Carthaginian general who led an army and war elephants across the Alps to challenge Rome. While scholars debate his exact route, Polybius and Livy clearly describe his movement up the left bank of the Rhône. Local tradition certainly remembers this: a path linking two hamlets above Seyssel is still called Chemin d’Annibal, which suggests he or some of his troops may have passed through our foothills.
Once Rome prevailed, things settled down. A Roman road ran through the valley, and excavations have uncovered coins, pottery, and a tomb discovered during 19th-century waterworks on the Haute-Savoie side. Artefacts confirm Seyssel was located near important Rhône transfer points linking Vienne to Geneva and handled many trade goods, including salt, timber, wine, cheese, and cloth.
A hoard of coins found in an iron pot during the 1860s included pieces issued under emperors from the 3rd and 4th centuries. The church of Seyssel-Haute-Savoie may stand on the site of a Roman temple to Jupiter, and some Roman stones have been unearthed and are on display there.
After the decline of Rome in the 5th century, a succession of Burgundian rulers, Frankish kings and Carolingian lords laid claim to the upper Rhône valley. Throughout these changes, Seyssel functioned as a single riverside settlement straddling the river crossing. Charlemagne passed through the region in the late 8th century, and after the Treaty of Verdun in 843, the valley fell within the shifting spheres of the Burgundian kingdoms and, later, the Holy Roman Empire. Borders moved around on paper, but locally, Seyssel remained one community organized around the river and its trade.
By the High Middle Ages, authority had stabilized. The region came under the control of the Counts, and later Dukes, of Savoy, and the House of Seyssel emerged as one of Savoy’s notable noble lineages, with its members appearing regularly in charters and regional records. The town grew on both banks of the Rhône, and a communal charter from the 13th century already mentions the feast of Saint Martin, celebrated each November 11, a tradition that continues to this day.
For centuries, no one questioned Seyssel’s unity.
How a treaty cut a town in half
Then in 1760 France and the Duchy of Savoy decided to tidy up their messy border and signed the Treaty of Turin. It split Seyssel in two and the Rhône became a proper boundary: one bank French, the other Savoyard.
The people of Seyssel protested. They asked for one parish, one administration, one market town, all tied to a single river economy that still meant something, but Paris and Turin wouldn’t listen and the town stayed divided.
With time, customs evolved and each side drew inward, running itself independently of the other. By the time Savoy joined France a century later, Seyssel already functioned as two communes in everything but daily life.
During World War II, Seyssel’s border position once again showed its strategic side. In June 1940, as German forces advanced south through eastern France, French troops deliberately destroyed Seyssel’s bridge over the Rhône to slow their progress. (The bridge seen today dates from the postwar period.)
Four years later, in February 1944, Nazi units operating under Klaus Barbie, head of the Gestapo in Lyon, carried out a brutal operation against the local Resistance: at least 11 people were executed and more than 20 deported, many of whom did not return. Plaques near the town’s school still commemorate those days. Seyssel was liberated on 24 August 1944, when American troops entered the town, ending four years of occupation.
In the decades since, the two communes have taken small steps toward cooperation. Some services are now pooled in a “greater Seyssel” agglomeration, allowing them to share resources without merging the communes themselves.
Fully uniting the towns, however, remains complicated. Merging would mean dismantling two administrations and starting over, choices that no one has felt able to make. The two sides aren’t rivals, but each wants to retain its identity, so the Rhône continues to separate them on paper even as daily life flows freely across the bridge.
🧲 The bridge that held Seyssel together
The Rhône has always been difficult to cross here (and nearly everywhere). A bridge existed in Roman times, but was replaced by barges and wooden structures that were often swept away by floods. Crossing the river was risky.
In the early 17th century, Seyssel finally built a stone bridge. At one end stood a small chapel, venerated by boatmen whose livelihoods depended on passing safely through the Rhône’s fast currents. A statue, Notre-Dame du Pont (Our Lady of the Bridge), watched over those who crossed, and a toll was charged for goods and maintenance. You can still see the statue in the Seyssel-Ain church.
For centuries, Seyssel was a river town in the truest sense, with the Rhône acting as a commercial highway between Savoy, Geneva and Switzerland. Seyssel was the endpoint because further navigation towards wasn’t possible. This is where goods were unloaded and stored, and warehouses lined the banks. Contemporaries called rivers “chemins qui marchent” (roads that move) and Seyssel sat at one of their key junctions.
The railway changed everything. River traffic declined, and by the late 19th century, only a few businesses remained: a small silk workshop, a lamp factory, a sawmill, an oil press, a few mills, and workshops for locksmiths and cobblers.
A divided town that lives as one
Today, many residents commute to Geneva, 45 minutes away by rail, while others rely on Annecy or Aix-les-Bains for work. When I first compared housing, Geneva offered me a cramped studio; Seyssel offered a farmhouse and space to breathe. The choice was easy.
Vineyards have replaced the river as the town’s characteristic homegrown business. There’s a local white wine called Seyssel, AOC since 1942, known for its light sparkle and made from Altesse and Molette grapes, the latter possibly introduced in the 15th century following the marriage of Louis of Savoy to Anne of Lusignan, a Cypriot princess. To avoid confusion between the two communes, bottles sometimes specify Seyssel-Ain or Seyssel-Haute-Savoie.
Every so often, the idea of a merger rears its head. Commissions are created, studies undertaken, but everyone walks away shaking their head, not quite sure how to get this done in practice.
Seyssel, it seems, thrives on being different, with each side of the town boasting its own subtle traits. We may not scream it from the rooftops, but we are quietly proud to be, how shall I say, “pas comme les autres”. Not like everyone else.
*Note: I don’t live in Seyssel proper but in an adjacent hamlet. Seyssel is where I go for life’s necessities.
From the travel blog
Culture, History and Civilizations of France: A Backstory for Beginners
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Resources
François Mugnier, Les Frontières de la Savoie du Nord (Mémoires et Documents de la Société Savoisienne d’Histoire et d’Archéologie, 1883)
Marc de Seyssel‑Cressieu, La Maison de Seyssel : ses origines, sa généalogie, son histoire d’après les documents originaux, Tomes 1 et 2, avec notes sur les familles alliées, les fiefs et les propriétés (1900) (Gallica)
Paul Guichonnet, Histoire de la Savoie (Editions Privat, 1973)
Seyssel et le commerce du Rhône – Gallica, BnF
Seyssel (Ain) – Wikipedia (French)
Seyssel (Haute‑Savoie) – Wikipedia (French)
Treaty of Turin – Wikipedia
What about a piece on the rapid growth of neo-druidism in the hills above Seyssel-Ain?
I've heard that amateur archeologists were able to determine that a spring-fed public washhouse was once the cultic site of a half-legendary college of druidesses.
Even though the druids were suppressed throughout Roman Gaul, their spiritual descendants still harvest mistletoe throughout the region just before the winter solstice every year.
I find this borderline between the two Seyssels fascinating. I imagine that reuniting the two municipalities would be almost impossible, considering that it would require changing the boundaries of two départements... and then which one, Ain or Haute-Savoie, would win the jackpot?