This document, written by Gualtiero, was mistranslated in the past, leading to errors made by later historiographers and scholars who interpreted the chapel as having been demolished, failing to identify its exact location. A careful reading and translation of the above-mentioned petition shows that Gualtiero was not asking the King for permission to demolish the Chapel, but to grant it to the Clerics of the Cathedral and their liturgical services. At the same time, he wanted to be able to move the mortal remains of the nobles of the royal family which were kept there to another place, by building a new chapel dedicated to Mary Magdalene. It should also be noted that the document is dated 1187,
the 21st year of William II's reign
, when the work of transforming the church had already been completed. It was reopened for worship on 6 April 1185, with a solemn consecration ceremony dedicated to the
Blessed Virgin of the Assumption
. The thesis that supported the belief in the chapel’s demolition was also based on a presumed rebuilding ab fundamentis of the Gualtierina Cathedral, shifting it a few metres from its former location as a former mosque and Byzantine basilica to the southern front.
