Archaeologists working at Posa Hill near Zeitz, Germany, have uncovered new evidence of an early medieval castle, an imposing bishop’s palace and sophisticated infrastructure belonging to a Benedictine monastery.
The latest discoveries come from the 2026 excavation campaign at Posaer Berg, where archaeological investigations have been under way since 2017. Research led by the State Office for Heritage Management and Archaeology of Saxony-Anhalt, working with the Zeitz Association for the Promotion of Archaeology and Historical Research, is providing new insights into more than 700 years of activity at the site.
This year’s work has concentrated particularly on the remains of a substantial fortified complex dating from the ninth and tenth centuries. Covering more than eight hectares, the stronghold occupied a strategically positioned hill overlooking the floodplain of the White Elster river.
For the first time, archaeologists have uncovered a significant concentration of early medieval features in the southern part of the inner bailey. Among the discoveries is a section of wall approximately 1.7 metres wide, which may have belonged to a ninth- or tenth-century castle tower.
Researchers believe the tower was connected to a defensive wall marking the southern boundary of the inner bailey. Following a fire in the late tenth century, the fortifications appear to have been shifted further south, allowing houses to be constructed over the former defensive area. Excavation of these structures has produced large quantities of pottery that could help establish a more precise chronology.
Imposing bishop’s palace uncovered
Research has also strengthened evidence that the castle became the seat of the Bishopric of Zeitz during the tenth century. The bishopric was established by Emperor Otto I in 968 as part of the creation of the Archdiocese of Magdeburg.
One of the most significant structures is the bishop’s palace, a monumental building thought to have stood several storeys high. Measuring approximately 18 metres wide, around 30 metres of the structure has been uncovered so far, although its complete dimensions remain unknown.
This season, archaeologists identified a north-to-south wall dividing the palace basement. One room retained a screed floor constructed over a carefully prepared layer of pebbles, demonstrating the considerable resources invested in the building. A broad opening was also identified in its southern wall.
The palace has architectural parallels with important medieval complexes at Paderborn, Goslar and Merseburg. Evidence that it once contained stained-glass windows – an exceptional feature for the period – further indicates the status of the episcopal complex.
Medieval monastery larger than previously thought
The excavations have also transformed archaeologists’ understanding of the Benedictine monastery established at Posa in 1114 by Bishop Dietrich I of Naumburg.
Researchers previously believed the monastery ended at the southern edge of a courtyard paved during the 16th century. Excavations have now shown that the complex extended considerably further south and included a second courtyard surrounded by additional buildings.
A small Romanesque building of uncertain purpose has been discovered in this area, while evidence from nearby structures includes the remains of two 14th-century warm-air heating systems and a high-quality red screed floor.
Among the most striking discoveries is part of a rare 14th-century clay water pipe. Around five metres of the pipeline has been investigated, revealing sections made from fired clay tubes approximately 70 centimetres long and 12 centimetres in diameter. Standardised ends allowed individual sections to be joined, with clay used to seal the connections.
Such early ceramic water pipes are exceptionally rare and have previously been documented at only a small number of monasteries and castles in southern Germany.
The discovery adds to evidence for an elaborate water-management system at Posa. Wooden pipes have also been found across the site, while written records document a water supply stretching more than four kilometres as early as 1168.
Together with the sophisticated heating systems, the newly discovered pipeline challenges earlier assumptions that Posa experienced a gradual decline during the later Middle Ages. Instead, archaeologists say the material evidence points to continued investment and considerable economic resources.
Posa is now regarded as one of the most extensively archaeologically investigated monastic sites in Central Germany. Excavations are continuing beyond the end of the student training campaign in mid-October, with researchers focusing on early medieval remains along the southern edge of the Carolingian-Ottonian stronghold.
Sources : LWL
