SUMMARY
The now ruined Church of St. Mary was once a royal chapel and collegiate church situated on the sandy tongue of land that made up the southern end of Oslo. Its building history, from a small wooden church to a Gothic structure with a monumental façade, reflects key architectural developments in the span of Nor-way’s Medieval Period (AD 1050–1537). Several excavations have shed light on this evolution, in which the question of form and dating has played a leading role. Central to the discussion are the excavations of Nicolay Nicolaysen (1868), Gerhard Fischer (1935) and Håkon Christie (1961–1963; 1969; 1971). This paper aims to examine the ruin and the many works dealing with St. Mary’s in Oslo, in order to present an overview of the scholarly discussion. We also revise some issues concerning building history, dating and architectural forms of the building. We suggest a new basis for a hypothetical reconstruction of the church as it may have looked at the death of Håkon V Magnusson in 1319.