Martyrium

A martyrium  is a church or shrine built over the tomb of a Christian martyr. It is associated with a specific architectural form, centered on a central element and thus built on a central plan, that is, of a circular or sometimes octagonal or cruciform shape.

The St. Philip Martyrium stands on top of the hill outside the northeastern section of the city walls. It dates from the 5th century. It was said that Philip was buried in the center of the building and, though his tomb has recently been unearthed, the exact location has not yet been verified. The Martyrium burned down at the end of the 5th or early 6th century, as attested by fire marks on the columns. Philip is said to have been martyred in Hierapolis by being crucified upside-down or by being hung upside down by his ankles from a tree.

The martyrium is usually taken to have been named after the Christian apostle Philip, but from early times there has been some dispute as to the actual identity of "Philip of Hierapolis". This confusion started with a report by Polycrates of Ephesus in his Eusebius's Ecclesiastical History and in his controversial letter written to Victor of Rome towards the end of the 2nd century. In the letter, he reports that the graves of Philip "of the twelve apostles", and of his two aged virgin daughters were in (the Phrygian) Hierapolis; a third daughter, "who had lived in the Holy Ghost", was buried at Ephesus. With this may be compared the testimony of Clement of Alexandria, who incidentally speaks of "Philip the Apostle" as having begotten children and as having given daughters in marriage.