The Basilica B’ in the archaeological site of Philippi dates back to the middle, approximately, of the sixth century AD and is an enigma in the history of architecture of the Justinian period of the Greek area. The present study attempts to clarify key issues of conflicting opinions that burden the relevant literature so far and to improve our knowledge on a number of unclear elements. In this context, the fact that the Basilica B’ was never completed as a building and did not function as a temple is documented, converging with the opinion of the excavator Paul Lemerle, while, at the same time, an attempt is made to determine the architect’s intentions regarding the design of the Basilica. Finally, the timeline of its construction phases is clarified and an attempt is made to determine the identity of the architect who undertook its design and construction. Text in Greek