Medieval Bishop’s Manor Unearthed in Turku’s Koroinen District
Archaeologists have discovered the remains of a rare medieval stone manor in Turku’s Koroinen district, believed to have belonged to a bishop. The find, made during excavations in June, sheds new light on Finland’s early ecclesiastical history.
The excavation, led by the University of Turku in collaboration with Svenska folkskolans vänner (SFV) rf, involved a research team and around 20 archaeology enthusiasts from Finland, Sweden, and the UK. The team examined a stone house ruin first identified in the 1970s, alongside searching for signs of Iron Age activity—though none were found (Yle).
The uncovered structure, at least 10 metres wide and multi-storeyed, featured floor levels, partition walls, and decorative limestone and brick details. Ilta-Sanomat reports that the building was likely heated by a tiled stove, a luxury indicating a wealthy owner. Among the artefacts recovered was a fragment of a Bohemian ribbed-stem goblet, dating to the late 14th or early 15th century, further suggesting the residence’s high status.
A Prestigious but Doomed Structure
University Lecturer in Archaeology Janne Harjula (University of Turku) noted that such stone houses are uncommon outside Turku’s medieval urban core. Preliminary findings suggest the manor was abandoned after the Reformation, later repurposed as a 17th-century romantic gazebo. The building’s demise was likely hastened by subsidence, a persistent issue in Turku due to its clay soil.
Professor of Archaeology Georg Haggrén explained that the structure showed signs of fire but was ultimately abandoned due to ground instability. The manor is believed to have been used by bishops Konrad Bitz and Maunu Särkilahti in the late 15th century (Ilta-Sanomat).
Historical Significance
Koroinen was once the administrative heart of Finland’s early church. The bishop’s seat moved to Turku in the early 14th century, and the peninsula’s ecclesiastical centre was fully abandoned by the 15th century. The estate later passed from church ownership to the city of Turku in the 1980s (Ilta-Sanomat).
Excavations also revealed the foundation of an 18th-century wooden outbuilding, previously unknown to researchers.
Future Research
The site has since been backfilled and restored. Further investigations are planned during medieval archaeology fieldwork courses in 2027 and 2028, aiming to clarify the building’s full extent, dating, and function (Yle).