Alcimoennis (aka Alkimoennis) was a Celtic Oppidum, or hill fort, located on the Michelsberg hill, dominating the peninsula between the Danube and Altmühl rivers in northern Bavaria, Germany, above the modern city of Kelheim. Although the peninsula has been more or less constantly inhabited since 13,000 BCE, the city as the Celts built it was founded around 500 BCE and abandoned again some time before Roman arrival in the area during the 1st century BCE. It is only identified once in historical documentation, namely in the copious works of the Greek geographer Ptolemy, who left us only the name and location of the city. Who exactly inhabited the city is also unclear. It appears to have been the central city for an unknown tribe, possibly a sub-tribe of the Vindelici centered in the nearby (and equally impressive) Oppidum of Manching.
The most visible surviving evidence of the city are its walls. The ramparts were 11 m wide and 2 m high, crossing the promontory between the rivers Altmühl and Danube. There is an inner defensive line enclosing 60 ha near the confluence, then a long outer rampart enclosing an enormous area of 630 ha, making it the largest Celtic settlement by land area. The defences also ran along the gentle bank of the river Altmühl north of the city for a total of over 10 km. There were four gates in the wall with wooden gatehouses.
Cliffs and steep slopes then protected the south-eastern side of the settlement along the Danube. A small promontory fort on the southern bank of the Danube, near the later Monastery of Weltenburg, has a series of short linear ramparts protecting a settlement in the bend of a meander. This is aligned with the end of the outer rampart on the far bank, dominating traffic on the river.
It would have taken at least 50 workers at least 70 years to build such a wall, evidence of the size and economic importance this settlement must have attained. Two 3 km stretches of the wall crossing the Danube-Altmühl peninsula are still clearly visible today.
The walls were built of thick timbered grids that were then filled with stone and earth and reinforced to the rear with a wide earth ramp. Kelheim has given its name to the pfostenschlitzmauer style of rampart construction characterized by vertical wooden posts set into the stone facing.
Very little remains of the settlement itself; stone construction was foreign to the Celts and their thatched-roofed wood structures have mostly disappeared over time. What we still have are the foundations of a few smaller structures (probably domiciles) and of a larger social, religious and defensive structure (viereckschanze). What appears to be a sacrificial altar has also been found. What nature did not bury human hands destroyed. Following his victory over the French in the early 19th century, the Bavarian King Louis I built a monumental "Liberation Hall" directly over the settlement's remains. During the same period, the construction of the King Louis Main-Danube canal through the Altmühl river valley destroyed the surviving bits of the northern wall as well as any evidence of the waterfront activities the city engaged in.
Numerous Bronze- and Iron-age graveyards dot the woods around Alcimoennis, and likely house deceased residents of the city itself. Despite their frequency, the graves are far too few to house the many inhabitants the city once had, which indicates that the city normally used alternative means of interment such as cremation for the majority of residents and reserved burial for important members of society. These graveyards have been the source of many astounding discoveries, including many impeccably preserved and elaborately decorated urns and the Steer of Michelsberg, a bronze figurine in the shape of a steer from around 200 BCE. Most of the known graveyards consist of groups of 1 to 2 meter high grave mounds that are still quite visible today, notably around the nearby village of Altessing.
Economically, the Alcimoennis thrived on iron. The surrounding soil contains large concentrations of iron, and the thick forests on all sides delivered adequate fuel for the smelting process. The landscape to the west of the settlement is literally covered in pock marks left by shallow mine shafts. The valleys around the city contained vast fields for farming as well as livestock, most notably swine. Fishing probably played an important role in every day life.
The abandonment of the city remains a mystery. There is no evidence that it saw a violent end. The layers of ash, remains of victims, and general chaos evident at places abandoned after a battle are absent. If the supposition that Alcimoennis belonged to the Vindelici is correct, then the city may have been abandoned after war with the Germanic Marcomanni tribe which moved in from the north. This nearly destroyed the Vindelici as a people and left their infrastructure in a shambles. In 15 BCE the Romans defeated and incorporated what remained of the Vindelici tribe and the area south of Arcimoenis became the province of Raetia. The so-called Devils Wall that ran the length of the Roman Limis ran straight through the ruins of the city, yet the Romans never made a single mention of it in their meticulous records, indicating total abandonment before their arrival. There is significant evidence that even though the city was abandoned, the life in the hinterland continued undisturbed. The iron mines did not cease work until the 10th century. The burials continued without pause, the only change being that the inhabitants interred remains in the Roman tradition.
- The Ancient Celts, Barry Cunliffe (1997) ISBN 0-14-025422-6
- Die Kelten, Alexander Demandt. Verlag C.H.Beck oHG, München 1998.