 Supporting this proposition is the fact that the Basilica Portiana, cited in many sources that were quoting the struggle of Ambrose to remove it from the Arians, has never been identified with certainty by archaeologists.A second proposition gives the date of the foundation of the church to a later period, between 390 and 402, and attributes its commissioning to Theodosius I or Stilicho.Evidence for this proposition comes from archaeological investigations carried out between 2002 and 2004.