The Church of the Holy Saviour is one of the most mysterious buildings in today's Krakow. The circumstances of its foundation are unknown – written sources point to Piotr Włostowic or one of the princes of Krakow. The original function and form of the building also remain unclear. Referring to the preserved documentation from archaeological research has resulted in new conclusions, verifying the existing hypotheses about the process of the temple's creation. In the introduction to the paper, I will present the current state of research in a summarised form. Then, the conclusions from the analysis of the preserved relics of the walls will be presented. These will form the basis for presenting a new concept of the church's medieval phases, supported by virtual reconstruction models. In the final phase, I will try to answer the question of whether, based on an interdisciplinary analysis of the data, it is possible to identify the church's founder.