The Freiburg Wall

In 2020, Freiburg will celebrate its 900th city anniversary. Duke Konrad of Zähringen awarded the right to hold a market to the small community of craft- and tradesmen who lived at the foot of the Schlossberg (castle hill) in 1120. The rights and duties of the new citizens were written down in a document called Stadtrodel (town document).

Tracing a city wall around the Freiburg market.
In 1240, the church was still the original one in Romanesque style dedicated to St. Nicolas.

Remarkably, the "new citizens" started protecting their community in the same year by building an enclosure wall, even leaving space inside the "ring" for future citizens and their trades.

A cut-through of Freiburg's first fortification

Archaeologist Dr. Betram Jenisch explained that the city wall was 10 to 11 meters high, more than one meter thick, and had an apron. The moat was 15 meters wide and 5 meters deep in most places. Two breast or abutment walls secured the outside berm of the moat and an inner circular road of 6 meters in width and 5 meters in height. Archaeological findings proved that existing buildings were demolished to build that robust construction along the Dreisam River.

Admire the beautiful house wall made of pebbles
unearthed in Freiburg a few years ago.

Dr. Jenisch stressed two local peculiarities. While city walls are grounded deeply and built straight up in most cases, the Freiburgers used a supporting apron to intercept the side pressure from the circular high road. Strangely, this advantageous Freiburg model was copied nowhere except at Neuenburg on the Rhine, a city founded by the Dukes of Zähringen later in 1175.

The Freiburg model of wall support was verified
 by archaeological diggings around the city ring.

The other Freiburg peculiarity is that the building material was unearthed locally, i.e., gravel excavated from the dug-out moat. In separating the gravel into various grain sizes, the builders gained boulders for the wall proper (30%), pebbles* for inner walls (see picture above), and sand (10%) for making mortar. The rest (60%) served as filling material for the circular road. During the work, nearly 200.000 cubic meters of excavated material was moved to correspond to 50.000 truckloads.
*Within the 60% estimated for the rest.

Sickinger Plan of 1589

So it is astonishing that the fortification was already finished by 1140, although gates and watchtowers, as seen on the Sickinger Plan of 1589, were still missing. Dendrochronological data reveal that the wooden beams of Freiburg's oldest gate, St. Martin, date back to 1202. It took the work of two additional generations to fill the holes in the wall, the entrances to the city, with proper gates.

How was all this financed? Most of the work was done by the citizens themselves. Still, the Stadtrodel included provisions in case of a succession: one-third of the heritage fell to the city earmarked ad aedificium (for building purposes).

When firearms dominated warfare, the old city wall became a joke. During the Thirty Years' War and, particularly during the aggressive French wars in the late 16th and early 18th centuries, artillery quickly opened breaches in the fortifications (Bresche schießen) several times.

When Freiburg became a French city in 1677, Sébastien Le Prestre de Vauban started surrounding the city with modern fortifications, thus integrating Freiburg into France's northern fortification belt. Contemporaries called his work “La dernière folie de Louis XIV. "

Vauban's masterpiece in flore.

When the French left Freiburg for good in 1745, they destroyed their fortifications. The city remained limited in its boundaries until the middle of the 19th century.

Freiburg in 1825. Vauban's remains mainly served as vineyards

Today, vestiges of Vauban's masterpiece are still visible in Freiburg's cityscape.

Vauban's fortifications were superimposed on present-day Freiburg.
1. The Colombischlössle, 2. The municipal theater, 3. University mensa (cafeteria),
4. Vauban's Breisach Gate, 5. Vestiges of moat and watchtower.
To the right, the ruins of Vauban's Schlossberg fortifications extending along the hill
are accessible to the public.

Dr. Jenisch's work is an outstanding example of how modern archaeology will enlarge the knowledge of historians.

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